Trusted proxies, unauthenticated rate limits and various fixes

.env.template

@@ -324,6 +324,14 @@
 ## Set to the string "none" (without quotes), to disable any headers and just use the remote IP
 # IP_HEADER=X-Real-IP
 
+## Which addresses the header above is accepted from, defaults to "local".
+## Anyone able to reach Vaultwarden can set the header, and the client IP is used for the login and
+## admin rate limits, so it is only trusted when the request comes from a proxy listed here.
+## "local" accepts it from any non global address, which covers a reverse proxy running on the same
+## host or container network. Use "all" to accept it from anywhere, or list the addresses of your
+## proxy as IPs and CIDR ranges if it connects from a public address.
+# IP_HEADER_TRUSTED_PROXIES=local
+
 ## Icon service
 ## The predefined icon services are: internal, bitwarden, duckduckgo, google.
 ## To specify a custom icon service, set a URL template with exactly one instance of `{}`,
@@ -461,6 +469,13 @@
 ## Note that this applies to both the login and the 2FA, so it's recommended to allow a burst size of at least 2.
 # LOGIN_RATELIMIT_MAX_BURST=10
 
+## Number of seconds, on average, between requests from the same IP address to one of the rate limited
+## unauthenticated endpoints, like the password hint, the account recovery mails or accessing a Send.
+# UNAUTHENTICATED_RATELIMIT_SECONDS=60
+## Allow a burst of requests of up to this size, while maintaining the average indicated by `UNAUTHENTICATED_RATELIMIT_SECONDS`.
+## This budget is shared between all of those endpoints, so it is more lenient than the login one.
+# UNAUTHENTICATED_RATELIMIT_MAX_BURST=50
+
 ## BETA FEATURE: Groups
 ## Controls whether group support is enabled for organizations
 ## This setting applies to organizations.

Cargo.lock

@@ -5922,6 +5922,7 @@ dependencies = [
  "hickory-resolver",
  "html5gum",
  "http 1.4.2",
+ "ipnet",
  "job_scheduler_ng",
  "jsonwebtoken",
  "lettre",

Cargo.toml

@@ -230,6 +230,9 @@ pico-args = "0.5.0"
 pastey = "0.2.3"
 governor = "0.10.4"
 
+# CIDR parsing for the trusted proxies of the client IP header
+ipnet = "2.12.0"
+
 # OIDC for SSO
 openidconnect = { version = "4.0.1", default-features = false }
 moka = { version = "0.12.15", features = ["future"] }

src/api/core/accounts.rs

@@ -15,7 +15,7 @@ use crate::{
         core::{accept_org_invite, log_user_event, two_factor::email},
         master_password_policy, register_push_device, unregister_push_device,
     },
-    auth::{ClientHeaders, Headers, decode_delete, decode_invite, decode_verify_email},
+    auth::{ClientHeaders, ClientIp, Headers, decode_delete, decode_invite, decode_verify_email},
     crypto,
     db::{
         DbConn, DbPool,
@@ -1197,7 +1197,9 @@ struct DeleteRecoverData {
 }
 
 #[post("/accounts/delete-recover", data = "<data>")]
-async fn post_delete_recover(data: Json<DeleteRecoverData>, conn: DbConn) -> EmptyResult {
+async fn post_delete_recover(data: Json<DeleteRecoverData>, ip: ClientIp, conn: DbConn) -> EmptyResult {
+    crate::ratelimit::check_limit_unauthenticated(&ip.ip)?;
+
     let data: DeleteRecoverData = data.into_inner();
 
     if CONFIG.mail_enabled() {
@@ -1270,9 +1272,11 @@ struct PasswordHintData {
 }
 
 #[post("/accounts/password-hint", data = "<data>")]
-async fn password_hint(data: Json<PasswordHintData>, conn: DbConn) -> EmptyResult {
+async fn password_hint(data: Json<PasswordHintData>, ip: ClientIp, conn: DbConn) -> EmptyResult {
     const NO_HINT: &str = "Sorry, you have no password hint...";
 
+    crate::ratelimit::check_limit_unauthenticated(&ip.ip)?;
+
     if !CONFIG.password_hints_allowed() || (!CONFIG.mail_enabled() && !CONFIG.show_password_hint()) {
         err!("This server is not configured to provide password hints.");
     }
@@ -1510,7 +1514,9 @@ async fn put_device_token(device_id: DeviceId, data: Json<PushToken>, headers: H
 }
 
 #[put("/devices/identifier/<device_id>/clear-token")]
-async fn put_clear_device_token(device_id: DeviceId, conn: DbConn) -> EmptyResult {
+async fn put_clear_device_token(device_id: DeviceId, ip: ClientIp, conn: DbConn) -> EmptyResult {
+    crate::ratelimit::check_limit_unauthenticated(&ip.ip)?;
+
     // This only clears push token
     // https://github.com/bitwarden/server/blob/9ebe16587175b1c0e9208f84397bb75d0d595510/src/Api/Controllers/DevicesController.cs#L215
     // https://github.com/bitwarden/server/blob/9ebe16587175b1c0e9208f84397bb75d0d595510/src/Core/Services/Implementations/DeviceService.cs#L37
@@ -1532,8 +1538,8 @@ async fn put_clear_device_token(device_id: DeviceId, conn: DbConn) -> EmptyResul
 
 // On upstream server, both PUT and POST are declared. Implementing the POST method in case it would be useful somewhere
 #[post("/devices/identifier/<device_id>/clear-token")]
-async fn post_clear_device_token(device_id: DeviceId, conn: DbConn) -> EmptyResult {
-    put_clear_device_token(device_id, conn).await
+async fn post_clear_device_token(device_id: DeviceId, ip: ClientIp, conn: DbConn) -> EmptyResult {
+    put_clear_device_token(device_id, ip, conn).await
 }
 
 #[get("/tasks")]

src/api/core/ciphers.rs

@@ -629,7 +629,7 @@ async fn post_ciphers_import(data: Json<ImportData>, headers: Headers, conn: DbC
 
     // Read and create the ciphers
     for (index, mut cipher_data) in data.ciphers.into_iter().enumerate() {
-        let folder_id = relations_map.get(&index).map(|i| folders[*i].clone());
+        let folder_id = relations_map.get(&index).and_then(|i| folders.get(*i).cloned());
         cipher_data.folder_id = folder_id;
 
         let mut cipher = Cipher::new(cipher_data.r#type, cipher_data.name.clone());
@@ -1043,6 +1043,13 @@ async fn share_cipher_by_uuid(
         err!("Cipher doesn't exist")
     };
 
+    // `update_cipher_from_data()` rejects this too, but only after the collections below were
+    // already linked. There are no transactions, so that would leave the cipher linked to a
+    // collection of another organization.
+    if cipher.organization_uuid.is_some() && cipher.organization_uuid != data.cipher.organization_id {
+        err!("Organization mismatch. Please resync the client before updating the cipher")
+    }
+
     let mut shared_to_collections = vec![];
 
     if let Some(organization_id) = &data.cipher.organization_id {

src/api/core/events.rs

@@ -182,7 +182,10 @@ async fn post_events_collect(data: Json<Vec<EventCollection>>, headers: Headers,
                 .await;
             }
             1600..=1699 => {
-                if let Some(org_id) = &event.organization_id {
+                // Only allow logging events for an organization the user is actually a member of.
+                if let Some(org_id) = &event.organization_id
+                    && Membership::find_confirmed_by_user_and_org(&headers.user.uuid, org_id, &conn).await.is_some()
+                {
                     log_event_impl(
                         event.r#type,
                         org_id,
@@ -197,8 +200,11 @@ async fn post_events_collect(data: Json<Vec<EventCollection>>, headers: Headers,
                 }
             }
             _ => {
+                // The cipher determines the organization the event is logged to, so make sure the
+                // user can actually access it instead of trusting the provided cipher uuid.
                 if let Some(cipher_uuid) = &event.cipher_id
                     && let Some(cipher) = Cipher::find_by_uuid(cipher_uuid, &conn).await
+                    && cipher.is_accessible_to_user(&headers.user.uuid, &conn).await
                     && let Some(org_id) = cipher.organization_uuid
                 {
                     log_event_impl(

src/api/core/organizations.rs

@@ -577,6 +577,13 @@ async fn post_bulk_access_collections(
         err!("Can't find organization details")
     }
 
+    // The collections and members are checked below, the groups only here.
+    let org_groups = Group::find_by_organization(&org_id, &conn).await;
+    let org_group_ids: HashSet<&GroupId> = org_groups.iter().map(|g| &g.uuid).collect();
+    if let Some(g) = data.groups.iter().find(|g| !org_group_ids.contains(&g.id)) {
+        err!("Invalid group", format!("Group {} does not belong to organization {}!", g.id, org_id))
+    }
+
     for col_id in data.collection_ids {
         let Some(collection) = Collection::find_by_uuid_and_org(&col_id, &org_id, &conn).await else {
             err!("Collection not found")
@@ -946,6 +953,11 @@ async fn get_members(
     if org_id != headers.membership.org_uuid {
         err!("Organization not found", "Organization id's do not match");
     }
+
+    if !headers.membership.has_full_access() {
+        err_code!("Resource not found.", "User does not have full access", rocket::http::Status::NotFound.code);
+    }
+
     let mut users_json = Vec::new();
     for u in Membership::find_by_org(&org_id, &conn).await {
         users_json.push(
@@ -1167,6 +1179,9 @@ async fn send_invite(
         }
 
         for group_id in &data.groups {
+            if Group::find_by_uuid_and_org(group_id, &org_id, &conn).await.is_none() {
+                err!("Group not found in Organization")
+            }
             let mut group_entry = GroupUser::new(group_id.clone(), new_member.uuid.clone());
             group_entry.save(&conn).await?;
         }
@@ -1614,6 +1629,9 @@ async fn edit_member(
     GroupUser::delete_all_by_member(&member_to_edit.uuid, &conn).await?;
 
     for group_id in data.groups.iter().flatten() {
+        if Group::find_by_uuid_and_org(group_id, &org_id, &conn).await.is_none() {
+            err!("Group not found in Organization")
+        }
         let mut group_entry = GroupUser::new(group_id.clone(), member_to_edit.uuid.clone());
         group_entry.save(&conn).await?;
     }
@@ -1813,19 +1831,19 @@ async fn post_org_import(
     // TODO: See if we can optimize the whole cipher adding/importing and prevent duplicate code and checks.
     Cipher::validate_cipher_data(&data.ciphers)?;
 
-    let existing_collections: HashSet<Option<CollectionId>> =
-        Collection::find_by_organization(&org_id, &conn).await.into_iter().map(|c| Some(c.uuid)).collect();
+    let existing_collections: HashMap<CollectionId, Collection> =
+        Collection::find_by_organization(&org_id, &conn).await.into_iter().map(|c| (c.uuid.clone(), c)).collect();
     let mut collections: Vec<CollectionId> = Vec::with_capacity(data.collections.len());
     for col in data.collections {
-        let collection_uuid = if existing_collections.contains(&col.id) {
-            let col_id = col.id.unwrap();
-            // When not an Owner or Admin, check if the member is allowed to access the collection.
+        let existing = col.id.as_ref().and_then(|col_id| existing_collections.get(col_id));
+        let collection_uuid = if let Some(collection) = existing {
+            // When not an Owner or Admin, check if the member is allowed to write to the collection.
             if headers.membership.atype < MembershipType::Admin
-                && !Collection::can_access_collection(&headers.membership, &col_id, &conn).await
+                && !collection.is_writable_by_user(&headers.membership.user_uuid, &conn).await
             {
                 err!(Compact, "The current user isn't allowed to manage this collection")
             }
-            col_id
+            collection.uuid.clone()
         } else {
             // We do not allow users or managers which can not manage all collections to create new collections
             // If there is any collection other than an existing import collection, abort the import.
@@ -1870,8 +1888,9 @@ async fn post_org_import(
 
     // Assign the collections
     for (cipher_index, col_index) in relations {
-        let cipher_id = &ciphers[cipher_index];
-        let col_id = &collections[col_index];
+        let (Some(cipher_id), Some(col_id)) = (ciphers.get(cipher_index), collections.get(col_index)) else {
+            err!(Compact, "Invalid collection relationship")
+        };
         CollectionCipher::save(cipher_id, col_id, &conn).await?;
     }
 
@@ -2441,6 +2460,11 @@ async fn get_groups_data(
     if org_id != headers.membership.org_uuid {
         err!("Organization not found", "Organization id's do not match");
     }
+
+    if !headers.membership.has_full_access() {
+        err_code!("Resource not found.", "User does not have full access", rocket::http::Status::NotFound.code);
+    }
+
     let groups: Vec<Value> = if CONFIG.org_groups_enabled() {
         let groups = Group::find_by_organization(&org_id, &conn).await;
         let mut groups_json = Vec::with_capacity(groups.len());

src/api/core/public.rs

@@ -14,7 +14,7 @@ use crate::{
     db::{
         DbConn,
         models::{
-            Group, GroupUser, Invitation, Membership, MembershipStatus, MembershipType, Organization,
+            Group, GroupUser, Invitation, Membership, MembershipStatus, MembershipType, OrgPolicy, Organization,
             OrganizationApiKey, OrganizationId, User,
         },
     },
@@ -84,8 +84,15 @@ async fn ldap_import(data: Json<OrgImportData>, token: PublicToken, conn: DbConn
             }
         // If user is part of the organization, restore it
         } else if let Some(mut member) = Membership::find_by_email_and_org(&user_data.email, &org_id, &conn).await {
-            let restored = member.restore();
+            let mut restored = member.restore();
             let ext_modified = member.set_external_id(Some(user_data.external_id.clone()));
+            // Enforce org policies as every other restore path does.
+            // If the user is not allowed, we revoke again and continue so the external_id is still updated.
+            if restored && let Err(e) = OrgPolicy::check_user_allowed(&member, "restore", &conn).await {
+                warn!("Not restoring {}: {e:?}", user_data.email);
+                member.revoke();
+                restored = false;
+            }
             if restored || ext_modified {
                 member.save(&conn).await?;
             }

src/api/core/sends.rs

@@ -471,6 +471,8 @@ async fn post_access_legacy(
     ip: ClientIp,
     nt: Notify<'_>,
 ) -> JsonResult {
+    crate::ratelimit::check_limit_unauthenticated(&ip.ip)?;
+
     let Some(mut send) = Send::find_by_access_id(access_id, &conn).await else {
         err_code!(SEND_INACCESSIBLE_MSG, 404)
     };
@@ -505,11 +507,13 @@ async fn post_access_legacy(
 
     // Files are incremented during the download
     if send.atype == SendType::Text as i32 {
-        send.access_count += 1;
+        if !send.register_access(&conn).await? {
+            err_code!(SEND_INACCESSIBLE_MSG, 404)
+        }
+    } else {
+        send.save(&conn).await?;
     }
 
-    send.save(&conn).await?;
-
     process_access(send, conn, nt).await
 }
 
@@ -548,8 +552,11 @@ async fn post_access_file_legacy(
     data: Json<SendAccessData>,
     host: Host,
     conn: DbConn,
+    ip: ClientIp,
     nt: Notify<'_>,
 ) -> JsonResult {
+    crate::ratelimit::check_limit_unauthenticated(&ip.ip)?;
+
     let Some(mut send) = Send::find_by_uuid(&send_id, &conn).await else {
         err_code!(SEND_INACCESSIBLE_MSG, 404)
     };
@@ -582,9 +589,9 @@ async fn post_access_file_legacy(
         }
     }
 
-    send.access_count += 1;
-
-    send.save(&conn).await?;
+    if !send.register_access(&conn).await? {
+        err_code!(SEND_INACCESSIBLE_MSG, 404)
+    }
 
     process_access_file(send, file_id, host, conn, nt).await
 }

src/api/icons.rs

@@ -405,6 +405,22 @@ async fn get_page(url: &str) -> Result<Response, Error> {
 }
 
 async fn get_page_with_referer(url: &str, referer: &str) -> Result<Response, Error> {
+    // The resolver only sees hosts needing name resolution, so IP-literal hrefs from
+    // attacker-controlled HTML never reach `post_resolve()`. Check them here.
+    let Ok(parsed_url) = url::Url::parse(url) else {
+        err_silent!("Invalid URL", url)
+    };
+
+    if !matches!(parsed_url.scheme(), "http" | "https") {
+        err_silent!("Invalid scheme", url)
+    }
+
+    let Some(host) = parsed_url.host() else {
+        err_silent!("Invalid host", url)
+    };
+
+    should_block_host(&host)?;
+
     let mut client = CLIENT.get(url);
     if !referer.is_empty() {
         client = client.header("Referer", referer);

src/api/identity.rs

@@ -109,6 +109,7 @@ async fn login(
         }
         "authorization_code" => err!("SSO sign-in is not available"),
         "send_access" => {
+            crate::ratelimit::check_limit_unauthenticated(&client_header.ip.ip)?;
             check_is_some(data.client_id.as_ref(), "client_id cannot be blank")?;
             check_is_some(data.send_id.as_ref(), "send_id cannot be blank")?;
 
@@ -1055,8 +1056,11 @@ enum RegisterVerificationResponse {
 #[post("/accounts/register/send-verification-email", data = "<data>")]
 async fn register_verification_email(
     data: Json<RegisterVerificationData>,
+    ip: ClientIp,
     conn: DbConn,
 ) -> ApiResult<RegisterVerificationResponse> {
+    crate::ratelimit::check_limit_unauthenticated(&ip.ip)?;
+
     let data = data.into_inner();
 
     // the registration can only continue if signup is allowed or there exists an invitation

src/api/notifications.rs

@@ -33,9 +33,14 @@ pub static WS_USERS: LazyLock<Arc<WebSocketUsers>> = LazyLock::new(|| {
 pub static WS_ANONYMOUS_SUBSCRIPTIONS: LazyLock<Arc<AnonymousWebSocketSubscriptions>> = LazyLock::new(|| {
     Arc::new(AnonymousWebSocketSubscriptions {
         map: Arc::new(dashmap::DashMap::new()),
+        connections: Arc::new(dashmap::DashMap::new()),
     })
 });
 
+/// The anonymous hub needs no authentication, so bound how much a single client can hold open.
+/// One connection is needed per pending login request, several at once are only expected behind NAT.
+const MAX_ANONYMOUS_CONNECTIONS_PER_IP: u32 = 25;
+
 static NOTIFICATIONS_DISABLED: LazyLock<bool> = LazyLock::new(|| !CONFIG.enable_websocket() && !CONFIG.push_enabled());
 
 pub fn routes() -> Vec<Route> {
@@ -82,14 +87,21 @@ impl Drop for WSEntryMapGuard {
 struct WSAnonymousEntryMapGuard {
     subscriptions: Arc<AnonymousWebSocketSubscriptions>,
     token: String,
+    entry_uuid: uuid::Uuid,
     addr: IpAddr,
 }
 
 impl WSAnonymousEntryMapGuard {
-    fn new(subscriptions: Arc<AnonymousWebSocketSubscriptions>, token: String, addr: IpAddr) -> Self {
+    fn new(
+        subscriptions: Arc<AnonymousWebSocketSubscriptions>,
+        token: String,
+        entry_uuid: uuid::Uuid,
+        addr: IpAddr,
+    ) -> Self {
         Self {
             subscriptions,
             token,
+            entry_uuid,
             addr,
         }
     }
@@ -98,7 +110,11 @@ impl WSAnonymousEntryMapGuard {
 impl Drop for WSAnonymousEntryMapGuard {
     fn drop(&mut self) {
         info!("Closing WS connection from {}", self.addr);
-        self.subscriptions.map.remove(&self.token);
+        if let Some(mut entry) = self.subscriptions.map.get_mut(&self.token) {
+            entry.retain(|(uuid, _)| uuid != &self.entry_uuid);
+        }
+        self.subscriptions.map.remove_if(&self.token, |_, senders| senders.is_empty());
+        self.subscriptions.release(self.addr);
     }
 }
 
@@ -194,12 +210,19 @@ fn anonymous_websockets_hub<'r>(ws: WebSocket, token: String, ip: ClientIp) -> R
     let (mut rx, guard) = {
         let subscriptions = Arc::clone(&WS_ANONYMOUS_SUBSCRIPTIONS);
 
-        // Add a channel to send messages to this client to the map
+        if !subscriptions.try_reserve(ip.ip) {
+            err_code!("Too many connections", 429)
+        }
+
+        // Add a channel to send messages to this client to the map.
+        // Clients reconnect with the same token while a login request is still pending, so keep
+        // every subscriber instead of replacing, otherwise the older one takes the newer one down.
         let (tx, rx) = tokio::sync::mpsc::channel::<Message>(100);
-        subscriptions.map.insert(token.clone(), tx);
+        let entry_uuid = uuid::Uuid::new_v4();
+        subscriptions.map.entry(token.clone()).or_default().push((entry_uuid, tx));
 
         // Once the guard goes out of scope, the connection will have been closed and the entry will be deleted from the map
-        (rx, WSAnonymousEntryMapGuard::new(subscriptions, token, ip.ip))
+        (rx, WSAnonymousEntryMapGuard::new(subscriptions, token, entry_uuid, ip.ip))
     };
 
     Ok({
@@ -534,15 +557,42 @@ impl WebSocketUsers {
 
 #[derive(Clone)]
 pub struct AnonymousWebSocketSubscriptions {
-    map: Arc<dashmap::DashMap<String, Sender<Message>>>,
+    map: Arc<dashmap::DashMap<String, Vec<UserSenders>>>,
+    connections: Arc<dashmap::DashMap<IpAddr, u32>>,
 }
 
 impl AnonymousWebSocketSubscriptions {
+    /// Takes a connection slot for this address, returns false when it already reached the limit.
+    fn try_reserve(&self, addr: IpAddr) -> bool {
+        let mut count = self.connections.entry(addr).or_insert(0);
+        if *count >= MAX_ANONYMOUS_CONNECTIONS_PER_IP {
+            return false;
+        }
+        *count += 1;
+        true
+    }
+
+    /// Releases a slot taken by `try_reserve`.
+    fn release(&self, addr: IpAddr) {
+        let empty = if let Some(mut count) = self.connections.get_mut(&addr) {
+            *count = count.saturating_sub(1);
+            *count == 0
+        } else {
+            false
+        };
+        // Only remove once the guard above is dropped, otherwise this deadlocks.
+        if empty {
+            self.connections.remove_if(&addr, |_, count| *count == 0);
+        }
+    }
+
     async fn send_update(&self, token: &str, data: &[u8]) {
-        if let Some(sender) = self.map.get(token).map(|v| v.clone())
-            && let Err(e) = sender.send(Message::binary(data)).await
-        {
-            error!("Error sending WS update {e}");
+        // Clone the senders so the map isn't kept locked while sending.
+        let senders = self.map.get(token).map(|v| v.clone()).unwrap_or_default();
+        for (_, sender) in senders {
+            if let Err(e) = sender.send(Message::binary(data)).await {
+                error!("Error sending WS update {e}");
+            }
         }
     }
 

src/auth.rs

@@ -10,6 +10,7 @@ use std::{
 };
 
 use chrono::{DateTime, TimeDelta, Utc};
+use ipnet::IpNet;
 use jsonwebtoken::{Algorithm, DecodingKey, EncodingKey, Header, errors::ErrorKind};
 use num_traits::FromPrimitive;
 use openssl::rsa::Rsa;
@@ -1054,12 +1055,44 @@ pub struct ClientIp {
     pub ip: IpAddr,
 }
 
+/// Parses a single entry of `ip_header_trusted_proxies`, which can be a CIDR range or a plain IP.
+pub fn parse_trusted_proxy(entry: &str) -> Option<IpNet> {
+    let entry = entry.trim();
+    match entry.parse::<IpNet>() {
+        Ok(net) => Some(net),
+        // Without a prefix length it is a single address, which is a valid way to write this.
+        Err(_) => entry.parse::<IpAddr>().ok().map(IpNet::from),
+    }
+}
+
+/// The client IP header can be set by anyone able to reach us, so only accept it from a proxy we trust.
+fn ip_header_is_trusted(remote: Option<IpAddr>) -> bool {
+    let trusted = CONFIG.ip_header_trusted_proxies();
+    let trusted = trusted.trim();
+    if trusted.eq_ignore_ascii_case("all") {
+        return true;
+    }
+
+    let Some(remote) = remote else {
+        return false;
+    };
+    // A dual stack listener reports IPv4 clients as IPv4-mapped IPv6, which `is_global()` reports as
+    // non global. That is what we want when blocking outgoing requests, but here it would trust them.
+    let remote = remote.to_canonical();
+    if trusted.eq_ignore_ascii_case("local") {
+        return !crate::util::is_global(remote);
+    }
+    trusted.split(',').filter_map(parse_trusted_proxy).any(|net| net.contains(&remote))
+}
+
 #[rocket::async_trait]
 impl<'r> FromRequest<'r> for ClientIp {
     type Error = ();
 
     async fn from_request(req: &'r Request<'_>) -> Outcome<Self, Self::Error> {
-        let ip = if CONFIG._ip_header_enabled() {
+        let remote = req.remote().map(|r| r.ip());
+
+        let ip = if CONFIG._ip_header_enabled() && ip_header_is_trusted(remote) {
             req.headers().get_one(&CONFIG.ip_header()).and_then(|ip| {
                 match ip.find(',') {
                     Some(idx) => &ip[..idx],
@@ -1070,10 +1103,13 @@ impl<'r> FromRequest<'r> for ClientIp {
                 .ok()
             })
         } else {
+            if CONFIG._ip_header_enabled() && req.headers().get_one(&CONFIG.ip_header()).is_some() {
+                debug!("Ignoring the '{}' header, {remote:?} is not a trusted proxy", CONFIG.ip_header());
+            }
             None
         };
 
-        let ip = ip.or_else(|| req.remote().map(|r| r.ip())).unwrap_or_else(|| "0.0.0.0".parse().unwrap());
+        let ip = ip.or(remote).unwrap_or_else(|| "0.0.0.0".parse().unwrap());
 
         Outcome::Success(ClientIp {
             ip,
@@ -1268,20 +1304,8 @@ pub async fn refresh_tokens(
 ) -> ApiResult<(Device, AuthTokens)> {
     let refresh_claims = match decode_refresh(refresh_token) {
         Err(err) => {
-            error!("Failed to decode {} refresh_token: {refresh_token}: {err:?}", ip.ip);
-            //err_silent!(format!("Impossible to read refresh_token: {}", err.message()))
-
-            // If the token failed to decode, it was probably one of the old style tokens that was just a Base64 string.
-            // We can generate a claim for them for backwards compatibility. Note that the password refresh claims don't
-            // check expiration or issuer, so they're not included here.
-            RefreshJwtClaims {
-                nbf: 0,
-                exp: 0,
-                iss: String::new(),
-                sub: AuthMethod::Password,
-                device_token: refresh_token.into(),
-                token: None,
-            }
+            error!("Failed to decode refresh_token from {}: {err:?}", ip.ip);
+            err_silent!("Invalid refresh token")
         }
         Ok(claims) => claims,
     };

src/auth/send.rs

@@ -113,8 +113,9 @@ impl SendTokens {
             }
         }
 
-        send.access_count += 1;
-        send.save(conn).await?;
+        if !send.register_access(conn).await? {
+            return Self::invalid_error(&format!("Send {send_id}, max access reached"), "send_id_invalid", true);
+        }
 
         Ok(Self {
             access_claims: generate_send_access_claims(&send_id),

src/config.rs

@@ -666,6 +666,12 @@ make_config! {
         ip_header:              String, true,   def,    "X-Real-IP".to_owned();
         /// Internal IP header property, used to avoid recomputing each time
         _ip_header_enabled:     bool,   false,  generated,    |c| &c.ip_header.trim().to_lowercase() != "none";
+        /// Trusted proxies |> Which addresses the client IP header is accepted from. Requests from any
+        /// other address use the remote IP instead, so a client can't spoof the header.
+        /// Either the string "local" (the default, any non-global address, which covers a reverse proxy
+        /// running on the same host or container network), the string "all" to accept it from anywhere,
+        /// or a comma separated list of IPs and CIDR ranges.
+        ip_header_trusted_proxies: String, true, def,    "local".to_owned();
         /// Icon service |> The predefined icon services are: internal, bitwarden, duckduckgo, google.
         /// To specify a custom icon service, set a URL template with exactly one instance of `{}`,
         /// which is replaced with the domain. For example: `https://icon.example.com/domain/{}`.
@@ -768,6 +774,11 @@ make_config! {
         /// Max burst size for login requests |> Allow a burst of requests of up to this size, while maintaining the average indicated by `login_ratelimit_seconds`. Note that this applies to both the login and the 2FA, so it's recommended to allow a burst size of at least 2
         login_ratelimit_max_burst:     u32, false, def, 10;
 
+        /// Seconds between unauthenticated requests |> Number of seconds, on average, between requests from the same IP address to any of the rate limited unauthenticated endpoints
+        unauthenticated_ratelimit_seconds:   u64, false, def, 60;
+        /// Max burst size for unauthenticated requests |> Allow a burst of requests of up to this size, while maintaining the average indicated by `unauthenticated_ratelimit_seconds`. This is shared between several endpoints, so it needs to be more lenient than the login one
+        unauthenticated_ratelimit_max_burst: u32, false, def, 50;
+
         /// Seconds between admin login requests |> Number of seconds, on average, between admin requests from the same IP address before rate limiting kicks in
         admin_ratelimit_seconds:       u64, false, def, 300;
         /// Max burst size for admin login requests |> Allow a burst of requests of up to this size, while maintaining the average indicated by `admin_ratelimit_seconds`
@@ -942,6 +953,18 @@ fn validate_config(cfg: &ConfigItems, on_update: bool) -> Result<(), Error> {
         }
     }
 
+    let trusted_proxies = cfg.ip_header_trusted_proxies.trim();
+    if !trusted_proxies.eq_ignore_ascii_case("all") && !trusted_proxies.eq_ignore_ascii_case("local") {
+        for entry in trusted_proxies.split(',').filter(|e| !e.trim().is_empty()) {
+            if crate::auth::parse_trusted_proxy(entry).is_none() {
+                err!(format!(
+                    "Invalid IP_HEADER_TRUSTED_PROXIES entry `{}`, expected an IP or CIDR range",
+                    entry.trim()
+                ));
+            }
+        }
+    }
+
     if cfg.password_iterations < 100_000 {
         err!("PASSWORD_ITERATIONS should be at least 100000 or higher. The default is 600000!");
     }

src/db/models/group.rs

@@ -271,7 +271,9 @@ impl Group {
             groups::table
                 .inner_join(groups_users::table.on(groups_users::groups_uuid.eq(groups::uuid)))
                 .inner_join(
-                    users_organizations::table.on(users_organizations::uuid.eq(groups_users::users_organizations_uuid)),
+                    users_organizations::table.on(users_organizations::uuid
+                        .eq(groups_users::users_organizations_uuid)
+                        .and(users_organizations::org_uuid.eq(groups::organizations_uuid))),
                 )
                 .filter(users_organizations::user_uuid.eq(user_uuid))
                 .filter(groups::organizations_uuid.eq(org_uuid))

src/db/models/send.rs

@@ -231,6 +231,37 @@ impl Send {
         }
     }
 
+    /// Registers an access, incrementing `access_count` only while below `max_access_count`.
+    /// Returns false when the limit was already reached. The check and the increment are a single
+    /// statement, otherwise concurrent accesses can both pass the check and exceed the limit.
+    pub async fn register_access(&mut self, conn: &DbConn) -> Result<bool, crate::Error> {
+        self.update_users_revision(conn).await;
+
+        let revision_date = Utc::now().naive_utc();
+        let uuid = self.uuid.clone();
+        let updated = conn
+            .run(move |conn| {
+                diesel::update(sends::table)
+                    .filter(sends::uuid.eq(uuid))
+                    .filter(
+                        sends::max_access_count
+                            .is_null()
+                            .or(sends::access_count.nullable().lt(sends::max_access_count)),
+                    )
+                    .set((sends::access_count.eq(sends::access_count + 1), sends::revision_date.eq(revision_date)))
+                    .execute(conn)
+            })
+            .await?;
+
+        if updated == 0 {
+            return Ok(false);
+        }
+
+        self.access_count += 1;
+        self.revision_date = revision_date;
+        Ok(true)
+    }
+
     pub async fn delete(&self, conn: &DbConn) -> EmptyResult {
         self.update_users_revision(conn).await;
 

src/http_client.rs

@@ -174,6 +174,27 @@ pub enum CustomHttpClientError {
 }
 
 impl CustomHttpClientError {
+    /// Attach the domain that resolved to this address, which `should_block_host()` can't know.
+    fn with_domain(self, name: &str) -> Self {
+        match self {
+            Self::NonGlobalIp {
+                ip,
+                ..
+            } => Self::NonGlobalIp {
+                domain: Some(name.to_owned()),
+                ip,
+            },
+            Self::Blocked {
+                domain,
+            } => Self::Blocked {
+                domain: format!("{name} ({domain})"),
+            },
+            other @ Self::Invalid {
+                ..
+            } => other,
+        }
+    }
+
     pub fn downcast_ref(e: &dyn std::error::Error) -> Option<&Self> {
         let mut source = e.source();
 
@@ -285,14 +306,12 @@ fn pre_resolve(name: &str, enforce_block: bool) -> Result<(), CustomHttpClientEr
 }
 
 fn post_resolve(name: &str, ip: IpAddr) -> Result<(), CustomHttpClientError> {
-    if should_block_ip(ip) {
-        Err(CustomHttpClientError::NonGlobalIp {
-            domain: Some(name.to_owned()),
-            ip,
-        })
-    } else {
-        Ok(())
-    }
+    let host: Host<&str> = match ip {
+        IpAddr::V4(ip) => Host::Ipv4(ip),
+        IpAddr::V6(ip) => Host::Ipv6(ip),
+    };
+
+    should_block_host(&host).map_err(|e| e.with_domain(name))
 }
 
 impl Resolve for CustomDns {

src/ratelimit.rs

@@ -18,6 +18,24 @@ static LIMITER_ADMIN: LazyLock<Limiter> = LazyLock::new(|| {
     RateLimiter::keyed(Quota::with_period(seconds).expect("Non-zero admin ratelimit seconds").allow_burst(burst))
 });
 
+static LIMITER_UNAUTHENTICATED: LazyLock<Limiter> = LazyLock::new(|| {
+    let seconds = Duration::from_secs(CONFIG.unauthenticated_ratelimit_seconds());
+    let burst = NonZeroU32::new(CONFIG.unauthenticated_ratelimit_max_burst())
+        .expect("Non-zero unauthenticated ratelimit burst");
+    RateLimiter::keyed(
+        Quota::with_period(seconds).expect("Non-zero unauthenticated ratelimit seconds").allow_burst(burst),
+    )
+});
+
+pub fn check_limit_unauthenticated(ip: &IpAddr) -> Result<(), Error> {
+    match LIMITER_UNAUTHENTICATED.check_key(ip) {
+        Ok(()) => Ok(()),
+        Err(_e) => {
+            err_code!("Too many requests", 429);
+        }
+    }
+}
+
 pub fn check_limit_login(ip: &IpAddr) -> Result<(), Error> {
     match LIMITER_LOGIN.check_key(ip) {
         Ok(()) => Ok(()),

src/sso_client.rs

@@ -95,7 +95,9 @@ impl<'c> AsyncHttpClient<'c> for OidcHttpClient {
             }
 
             let body = response.bytes().await.map_err(Box::new)?;
-            debug!("Response body {}", String::from_utf8_lossy(&body));
+            if CONFIG.sso_debug_tokens() {
+                debug!("Response body {}", String::from_utf8_lossy(&body));
+            }
             builder.body(body.to_vec()).map_err(HttpClientError::Http)
         })
     }