core: set pointers to NULL after free of data when a buffer is closed (issue #2332)

bound the configured proxy username and password before they are copied into the fixed stack buffer in network_pass_socks5proxy, otherwise a login longer than the buffer (a long password or token) overruns it while building the SOCKS5 auth request.

CHANGELOG.md

@@ -6,6 +6,14 @@ SPDX-License-Identifier: GPL-3.0-or-later
 
 # WeeChat ChangeLog
 
+## Version 4.9.3 (under dev)
+
+### Fixed
+
+- core: fix buffer overflow in connection to SOCKS5 proxy ([#2325](https://github.com/weechat/weechat/issues/2325))
+- relay/api: fix memory leak in resources "handshake", "input" and "completion"
+- xfer: fix out-of-bounds write in xfer file transfer resume ([#2326](https://github.com/weechat/weechat/issues/2326))
+
 ## Version 4.9.2 (2026-06-07)
 
 ### Fixed
@@ -25,9 +33,9 @@ SPDX-License-Identifier: GPL-3.0-or-later
 
 - core: fix option weechat.look.color_real_white not applied when color is "white" on 16+ colors terminals ([#1742](https://github.com/weechat/weechat/issues/1742))
 - irc: fix tag in message with list of names when joining a channel
-- relay: limit size of decompressed websocket frame with permessage-deflate to prevent memory exhaustion ([GHSA-v2v4-45wm-5cr3](https://github.com/weechat/weechat/security/advisories/GHSA-v2v4-45wm-5cr3))
-- relay: fix timing attack on password authentication ([GHSA-vhv8-g2r9-cwcc](https://github.com/weechat/weechat/security/advisories/GHSA-vhv8-g2r9-cwcc))
-- api, relay: fix timing attack on TOTP validation ([GHSA-vhv8-g2r9-cwcc](https://github.com/weechat/weechat/security/advisories/GHSA-vhv8-g2r9-cwcc))
+- relay: limit size of decompressed websocket frame with permessage-deflate to prevent memory exhaustion ([GHSA-v2v4-45wm-5cr3](https://github.com/weechat/weechat/security/advisories/GHSA-v2v4-45wm-5cr3), [CVE-2026-53524](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2026-53524))
+- relay: fix timing attack on password authentication ([GHSA-vhv8-g2r9-cwcc](https://github.com/weechat/weechat/security/advisories/GHSA-vhv8-g2r9-cwcc), [CVE-2026-53525](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2026-53525))
+- api, relay: fix timing attack on TOTP validation ([GHSA-vhv8-g2r9-cwcc](https://github.com/weechat/weechat/security/advisories/GHSA-vhv8-g2r9-cwcc), [CVE-2026-53525](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2026-53525))
 
 ## Version 4.9.0 (2026-03-29)
 

doc/en/weechat_relay_api.en.adoc

@@ -1028,6 +1028,13 @@ Path parameters:
   confused with the buffer number, which is different)
 * `buffer_name` (string, **required**): buffer name
 
+Query parameters:
+
+* `colors` (string, optional, default: `ansi`): how to return strings with color codes:
+** `ansi`: return ANSI color codes
+** `weechat`: return WeeChat internal color codes
+** `strip`: strip colors
+
 Request example: get nicks of a buffer:
 
 [source,shell]

doc/fr/weechat_relay_api.fr.adoc

@@ -1040,6 +1040,14 @@ Paramètres de chemin :
   confondre avec le numéro du tampon, qui est différent)
 * `buffer_name` (chaîne, **obligatoire**) : nom du tampon
 
+Paramètres de requête :
+
+* `colors` (chaîne, facultatif, par défaut : `ansi`) : comment les chaînes avec
+  des couleurs sont retournées :
+** `ansi` : retourner les codes couleur ANSI
+** `weechat` : retourner les codes couleur internes WeeChat
+** `strip` : supprimer les couleurs
+
 Exemple de requête : obtenir les pseudos d'un tampon :
 
 [source,shell]

doc/sr/weechat_relay_api.sr.adoc

@@ -1024,12 +1024,19 @@ GET /api/buffers/{id_бафера}/nicks
 GET /api/buffers/{име_бафера}/nicks
 ----
 
-Параметри упита:
+Параметри путање:
 
 * `id_бафера` (цео број, **обавезно**): јединствени идентификатор бафера (не треба
   да се помеша са бројем бафера, то је нешто друго)
 * `име_бафера` (стринг, **обавезно**): име бафера
 
+Параметри упита:
+
+* `colors` (стринг, није обавезно, подразумевано: `ansi`): како се враћају стрингови са кодовима боје:
+** `ansi`: враћају се ANSI кодови боје
+** `weechat`: враћају се WeeChat интерни кодови боје
+** `strip`: уклањају се боје
+
 Пример захтева: врати надимке бафера:
 
 [source,shell]

src/core/core-network.c

@@ -581,7 +581,13 @@ network_pass_socks5proxy (struct t_proxy *proxy, int sock, const char *address,
                           int port)
 {
     struct t_network_socks5 socks5;
-    unsigned char buffer[288];
+    /*
+     * buffer must be large enough for the username/password authentication
+     * request, which is the longest message sent/received here; according to
+     * RFC 1929 it is: version (1) + username length (1) + username (max 255)
+     * + password length (1) + password (max 255)
+     */
+    unsigned char buffer[2 + 255 + 1 + 255];
     int username_len, password_len, addr_len, addr_buffer_len;
     unsigned char *addr_buffer;
     char *username, *password;
@@ -630,6 +636,18 @@ network_pass_socks5proxy (struct t_proxy *proxy, int sock, const char *address,
         username_len = strlen (username);
         password_len = strlen (password);
 
+        /*
+         * username and password length are each stored on a single byte
+         * (RFC 1929), so they cannot exceed 255 bytes: reject longer values,
+         * otherwise the memcpy calls below would overflow the buffer
+         */
+        if ((username_len > 255) || (password_len > 255))
+        {
+            free (username);
+            free (password);
+            return 0;
+        }
+
         /* make username/password buffer */
         buffer[0] = 1;
         buffer[1] = (unsigned char) username_len;

src/gui/gui-buffer.c

@@ -3804,6 +3804,7 @@ gui_buffer_close (struct t_gui_buffer *buffer)
 
     gui_hotlist_remove_buffer (buffer, 1);
     free (buffer->hotlist_removed);
+    buffer->hotlist_removed = NULL;
     if (gui_hotlist_initial_buffer == buffer)
         gui_hotlist_initial_buffer = NULL;
 
@@ -3822,55 +3823,85 @@ gui_buffer_close (struct t_gui_buffer *buffer)
     /* free all lines */
     gui_line_free_all (buffer);
     free (buffer->own_lines);
+    buffer->own_lines = NULL;
     free (buffer->mixed_lines);
+    buffer->mixed_lines = NULL;
 
     /* free some data */
     gui_buffer_undo_free_all (buffer);
     gui_history_buffer_free (buffer);
     gui_completion_free (buffer->completion);
+    buffer->completion = NULL;
     gui_nicklist_remove_all (buffer);
     gui_nicklist_remove_group (buffer, buffer->nicklist_root);
+    buffer->nicklist_root = NULL;
     hashtable_free (buffer->hotlist_max_level_nicks);
+    buffer->hotlist_max_level_nicks = NULL;
     gui_key_free_all (-1, &buffer->keys, &buffer->last_key,
                       &buffer->keys_count, 0);
     gui_buffer_local_var_remove_all (buffer);
     hashtable_free (buffer->local_variables);
+    buffer->local_variables = NULL;
     free (buffer->plugin_name_for_upgrade);
+    buffer->plugin_name_for_upgrade = NULL;
     free (buffer->name);
+    buffer->name = NULL;
     free (buffer->full_name);
+    buffer->full_name = NULL;
     free (buffer->old_full_name);
+    buffer->old_full_name = NULL;
     free (buffer->short_name);
+    buffer->short_name = NULL;
     free (buffer->title);
+    buffer->title = NULL;
     free (buffer->modes);
+    buffer->modes = NULL;
     free (buffer->input_prompt);
+    buffer->input_prompt = NULL;
     free (buffer->input_buffer);
+    buffer->input_buffer = NULL;
     free (buffer->input_undo_snap);
+    buffer->input_undo_snap = NULL;
     free (buffer->text_search_input);
+    buffer->text_search_input = NULL;
     if (buffer->text_search_regex_compiled)
     {
         regfree (buffer->text_search_regex_compiled);
         free (buffer->text_search_regex_compiled);
+        buffer->text_search_regex_compiled = NULL;
     }
     free (buffer->highlight_words);
+    buffer->highlight_words = NULL;
     free (buffer->highlight_disable_regex);
+    buffer->highlight_disable_regex = NULL;
     if (buffer->highlight_disable_regex_compiled)
     {
         regfree (buffer->highlight_disable_regex_compiled);
         free (buffer->highlight_disable_regex_compiled);
+        buffer->highlight_disable_regex_compiled = NULL;
     }
     free (buffer->highlight_regex);
+    buffer->highlight_regex = NULL;
     if (buffer->highlight_regex_compiled)
     {
         regfree (buffer->highlight_regex_compiled);
         free (buffer->highlight_regex_compiled);
+        buffer->highlight_regex_compiled = NULL;
     }
     free (buffer->highlight_tags_restrict);
+    buffer->highlight_tags_restrict = NULL;
     string_free_split_tags (buffer->highlight_tags_restrict_array);
+    buffer->highlight_tags_restrict_array = NULL;
     free (buffer->highlight_tags);
+    buffer->highlight_tags = NULL;
     string_free_split_tags (buffer->highlight_tags_array);
+    buffer->highlight_tags_array = NULL;
     free (buffer->input_callback_data);
+    buffer->input_callback_data = NULL;
     free (buffer->close_callback_data);
+    buffer->close_callback_data = NULL;
     free (buffer->nickcmp_callback_data);
+    buffer->nickcmp_callback_data = NULL;
 
     /* remove buffer from buffers list */
     if (buffer->prev_buffer)

src/plugins/relay/api/relay-api-protocol.c

@@ -402,7 +402,10 @@ RELAY_API_PROTOCOL_CALLBACK(handshake)
     if (json_body)
     {
         if (!cJSON_IsObject (json_body))
+        {
+            cJSON_Delete (json_body);
             return RELAY_API_PROTOCOL_RC_BAD_REQUEST;
+        }
         json_algos = cJSON_GetObjectItem (json_body, "password_hash_algo");
         if (json_algos)
         {
@@ -781,8 +784,13 @@ RELAY_API_PROTOCOL_CALLBACK(input)
     char str_delay[32];
 
     json_body = cJSON_Parse (client->http_req->body);
-    if (!json_body || !cJSON_IsObject (json_body))
+    if (!json_body)
         return RELAY_API_PROTOCOL_RC_BAD_REQUEST;
+    if (!cJSON_IsObject (json_body))
+    {
+        cJSON_Delete (json_body);
+        return RELAY_API_PROTOCOL_RC_BAD_REQUEST;
+    }
 
     /* get buffer either by name or by id */
     ptr_buffer = NULL;
@@ -908,8 +916,13 @@ RELAY_API_PROTOCOL_CALLBACK(completion)
     struct t_gui_buffer *ptr_buffer;
 
     json_body = cJSON_Parse (client->http_req->body);
-    if (!json_body || !cJSON_IsObject(json_body))
+    if (!json_body)
         return RELAY_API_PROTOCOL_RC_BAD_REQUEST;
+    if (!cJSON_IsObject(json_body))
+    {
+        cJSON_Delete (json_body);
+        return RELAY_API_PROTOCOL_RC_BAD_REQUEST;
+    }
 
     /* get buffer either by name or by id */
     ptr_buffer = NULL;

src/plugins/xfer/xfer-dcc.c

@@ -242,8 +242,8 @@ int
 xfer_dcc_resume_hash (struct t_xfer *xfer)
 {
     char *buf;
-    unsigned long long total_read;
-    ssize_t length_buf, to_read, num_read;
+    unsigned long long total_read, length_buf, to_read;
+    ssize_t num_read;
     int ret, fd;
 
     total_read = 0;