Package: release.debian.org
Severity: normal
Tags: trixie
X-Debbugs-Cc: [email protected], [email protected]
Control: affects -1 + src:civetweb
User: [email protected]
Usertags: pu
* CVE-2025-9648: Infinite loop in mg_handle_form_request
(Closes: #1118285)
* CVE-2025-55763: Buffer overflow in the URI parser
(Closes: #1112507)
diffstat for civetweb-1.16+dfsg civetweb-1.16+dfsg
changelog | 10
patches/0001-Make-parsing-of-URL-encoded-forms-more-robust.patch | 246
++++++++++
patches/CVE-2025-55763.patch | 86 +++
patches/series | 2
4 files changed, 344 insertions(+)
diff -Nru civetweb-1.16+dfsg/debian/changelog
civetweb-1.16+dfsg/debian/changelog
--- civetweb-1.16+dfsg/debian/changelog 2024-07-20 00:23:09.000000000 +0300
+++ civetweb-1.16+dfsg/debian/changelog 2026-03-07 11:54:47.000000000 +0200
@@ -1,3 +1,13 @@
+civetweb (1.16+dfsg-2+deb13u1) trixie; urgency=medium
+
+ * Non-maintainer upload.
+ * CVE-2025-9648: Infinite loop in mg_handle_form_request
+ (Closes: #1118285)
+ * CVE-2025-55763: Buffer overflow in the URI parser
+ (Closes: #1112507)
+
+ -- Adrian Bunk <[email protected]> Sat, 07 Mar 2026 11:54:47 +0200
+
civetweb (1.16+dfsg-2) unstable; urgency=medium
* Unfuzz patches.
diff -Nru
civetweb-1.16+dfsg/debian/patches/0001-Make-parsing-of-URL-encoded-forms-more-robust.patch
civetweb-1.16+dfsg/debian/patches/0001-Make-parsing-of-URL-encoded-forms-more-robust.patch
---
civetweb-1.16+dfsg/debian/patches/0001-Make-parsing-of-URL-encoded-forms-more-robust.patch
1970-01-01 02:00:00.000000000 +0200
+++
civetweb-1.16+dfsg/debian/patches/0001-Make-parsing-of-URL-encoded-forms-more-robust.patch
2026-03-06 22:51:24.000000000 +0200
@@ -0,0 +1,246 @@
+From e947ee9bae82ab5035ccc48430d820bc3968ac77 Mon Sep 17 00:00:00 2001
+From: bel2125 <[email protected]>
+Date: Tue, 2 Sep 2025 14:08:41 +0200
+Subject: Make parsing of URL encoded forms more robust
+
+Reject requests that obviously violate the URL encoding.
+Fixes #1348
+---
+ src/civetweb.c | 5 +++++
+ src/handle_form.inl | 46 +++++++++++++++++++++++++++++++++++++--------
+ 2 files changed, 43 insertions(+), 8 deletions(-)
+
+diff --git a/src/civetweb.c b/src/civetweb.c
+index 3e93d570..1f13f3f4 100644
+--- a/src/civetweb.c
++++ b/src/civetweb.c
+@@ -7052,6 +7052,7 @@ mg_url_decode(const char *src,
+ int is_form_url_encoded)
+ {
+ int i, j, a, b;
++
+ #define HEXTOI(x) (isdigit(x) ? (x - '0') : (x - 'W'))
+
+ for (i = j = 0; (i < src_len) && (j < (dst_len - 1)); i++, j++) {
+@@ -7064,11 +7065,15 @@ mg_url_decode(const char *src,
+ i += 2;
+ } else if (is_form_url_encoded && (src[i] == '+')) {
+ dst[j] = ' ';
++ } else if ((unsigned char)src[i] <= ' ') {
++ return -1; /* invalid character */
+ } else {
+ dst[j] = src[i];
+ }
+ }
+
++#undef HEXTOI
++
+ dst[j] = '\0'; /* Null-terminate the destination */
+
+ return (i >= src_len) ? j : -1;
+diff --git a/src/handle_form.inl b/src/handle_form.inl
+index be477a05..0ebaf560 100644
+--- a/src/handle_form.inl
++++ b/src/handle_form.inl
+@@ -1,4 +1,4 @@
+-/* Copyright (c) 2016-2021 the Civetweb developers
++/* Copyright (c) 2016-2025 the Civetweb developers
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
copy
+ * of this software and associated documentation files (the "Software"), to
deal
+@@ -39,7 +39,7 @@ url_encoded_field_found(const struct mg_connection *conn,
+ mg_url_decode(key, (int)key_len, key_dec, (int)sizeof(key_dec), 1);
+
+ if (((size_t)key_dec_len >= (size_t)sizeof(key_dec)) || (key_dec_len <
0)) {
+- return MG_FORM_FIELD_STORAGE_SKIP;
++ return MG_FORM_FIELD_STORAGE_ABORT;
+ }
+
+ if (filename) {
+@@ -53,7 +53,7 @@ url_encoded_field_found(const struct mg_connection *conn,
+ || (filename_dec_len < 0)) {
+ /* Log error message and skip this field. */
+ mg_cry_internal(conn, "%s: Cannot decode filename",
__func__);
+- return MG_FORM_FIELD_STORAGE_SKIP;
++ return MG_FORM_FIELD_STORAGE_ABORT;
+ }
+ remove_dot_segments(filename_dec);
+
+@@ -95,6 +95,7 @@ url_encoded_field_get(
+ struct mg_form_data_handler *fdh)
+ {
+ char key_dec[1024];
++ int key_dec_len;
+
+ char *value_dec = (char *)mg_malloc_ctx(*value_len + 1, conn->phys_ctx);
+ int value_dec_len, ret;
+@@ -108,7 +109,8 @@ url_encoded_field_get(
+ return MG_FORM_FIELD_STORAGE_ABORT;
+ }
+
+- mg_url_decode(key, (int)key_len, key_dec, (int)sizeof(key_dec), 1);
++ key_dec_len = mg_url_decode(
++ key, (int)key_len, key_dec, (int)sizeof(key_dec), 1);
+
+ if (*value_len >= 2 && value[*value_len - 2] == '%')
+ *value_len -= 2;
+@@ -117,6 +119,11 @@ url_encoded_field_get(
+ value_dec_len = mg_url_decode(
+ value, (int)*value_len, value_dec, ((int)*value_len) + 1, 1);
+
++ if ((key_dec_len < 0) || (value_dec_len < 0)) {
++ mg_free(value_dec);
++ return MG_FORM_FIELD_STORAGE_ABORT;
++ }
++
+ ret = fdh->field_get(key_dec,
+ value_dec,
+ (size_t)value_dec_len,
+@@ -136,9 +143,13 @@ unencoded_field_get(const struct mg_connection *conn,
+ struct mg_form_data_handler *fdh)
+ {
+ char key_dec[1024];
++ int key_dec_len;
+ (void)conn;
+
+- mg_url_decode(key, (int)key_len, key_dec, (int)sizeof(key_dec), 1);
++ key_dec_len = mg_url_decode(key, (int)key_len, key_dec,
(int)sizeof(key_dec), 1);
++ if (key_dec_len < 0) {
++ return MG_FORM_FIELD_STORAGE_ABORT;
++ }
+
+ return fdh->field_get(key_dec, value, value_len, fdh->user_data);
+ }
+@@ -188,6 +199,7 @@ mg_handle_form_request(struct mg_connection *conn,
+ int buf_fill = 0;
+ int r;
+ int field_count = 0;
++ int abort_read = 0;
+ struct mg_file fstore = STRUCT_FILE_INITIALIZER;
+ int64_t file_size = 0; /* init here, to a avoid a false positive
+ "uninitialized variable used" warning */
+@@ -278,6 +290,7 @@ mg_handle_form_request(struct mg_connection *conn,
+ conn, data, (size_t)keylen, val, (size_t
*)&vallen, fdh);
+ if (r == MG_FORM_FIELD_HANDLE_ABORT) {
+ /* Stop request handling */
++ abort_read = 1;
+ break;
+ }
+ if (r == MG_FORM_FIELD_HANDLE_NEXT) {
+@@ -320,6 +333,7 @@ mg_handle_form_request(struct mg_connection *conn,
+ r = field_stored(conn,
path, file_size, fdh);
+ if (r ==
MG_FORM_FIELD_HANDLE_ABORT) {
+ /* Stop request
handling */
++ abort_read = 1;
+ break;
+ }
+
+@@ -358,6 +372,7 @@ mg_handle_form_request(struct mg_connection *conn,
+ if ((field_storage & MG_FORM_FIELD_STORAGE_ABORT)
+ == MG_FORM_FIELD_STORAGE_ABORT) {
+ /* Stop parsing the request */
++ abort_read = 1;
+ break;
+ }
+
+@@ -386,7 +401,7 @@ mg_handle_form_request(struct mg_connection *conn,
+ * Here we use "POST", and read the data from the request body.
+ * The data read on the fly, so it is not required to buffer the
+ * entire request in memory before processing it. */
+- for (;;) {
++ while (!abort_read) {
+ const char *val;
+ const char *next;
+ ptrdiff_t keylen, vallen;
+@@ -440,6 +455,7 @@ mg_handle_form_request(struct mg_connection *conn,
+ if ((field_storage & MG_FORM_FIELD_STORAGE_ABORT)
+ == MG_FORM_FIELD_STORAGE_ABORT) {
+ /* Stop parsing the request */
++ abort_read = 1;
+ break;
+ }
+
+@@ -468,6 +484,15 @@ mg_handle_form_request(struct mg_connection *conn,
+ } else {
+ vallen = (ptrdiff_t)strlen(val);
+ end_of_key_value_pair_found =
all_data_read;
++ if ((buf + buf_fill) > (val + vallen)) {
++ /* Avoid DoS attacks by having
a zero byte in the middle of
++ * a request that is supposed
to be URL encoded. Since this
++ * request is certainly
invalid, according to the protocol
++ * specification, stop
processing it. Fixes #1348 */
++ abort_read = 1;
++ break;
++ }
++
+ }
+
+ if (field_storage == MG_FORM_FIELD_STORAGE_GET)
{
+@@ -489,6 +514,7 @@ mg_handle_form_request(struct mg_connection *conn,
+ get_block++;
+ if (r == MG_FORM_FIELD_HANDLE_ABORT) {
+ /* Stop request handling */
++ abort_read = 1;
+ break;
+ }
+ if (r == MG_FORM_FIELD_HANDLE_NEXT) {
+@@ -557,7 +583,6 @@ mg_handle_form_request(struct mg_connection *conn,
+ val = buf;
+ }
+ }
+-
+ } while (!end_of_key_value_pair_found);
+
+ #if !defined(NO_FILESYSTEMS)
+@@ -568,6 +593,7 @@ mg_handle_form_request(struct mg_connection *conn,
+ r = field_stored(conn, path, file_size,
fdh);
+ if (r == MG_FORM_FIELD_HANDLE_ABORT) {
+ /* Stop request handling */
++ abort_read = 1;
+ break;
+ }
+ } else {
+@@ -581,7 +607,7 @@ mg_handle_form_request(struct mg_connection *conn,
+ }
+ #endif /* NO_FILESYSTEMS */
+
+- if (all_data_read && (buf_fill == 0)) {
++ if ((all_data_read && (buf_fill == 0)) || abort_read) {
+ /* nothing more to process */
+ break;
+ }
+@@ -937,6 +963,7 @@ mg_handle_form_request(struct mg_connection *conn,
+ get_block++;
+ if (r == MG_FORM_FIELD_HANDLE_ABORT) {
+ /* Stop request handling */
++ abort_read = 1;
+ break;
+ }
+ if (r == MG_FORM_FIELD_HANDLE_NEXT) {
+@@ -1011,6 +1038,7 @@ mg_handle_form_request(struct mg_connection *conn,
+ fdh);
+ if (r == MG_FORM_FIELD_HANDLE_ABORT) {
+ /* Stop request handling */
++ abort_read = 1;
+ break;
+ }
+ if (r == MG_FORM_FIELD_HANDLE_NEXT) {
+@@ -1039,6 +1067,7 @@ mg_handle_form_request(struct mg_connection *conn,
+ r = field_stored(conn,
path, file_size, fdh);
+ if (r ==
MG_FORM_FIELD_HANDLE_ABORT) {
+ /* Stop request
handling */
++ abort_read = 1;
+ break;
+ }
+ } else {
+@@ -1057,6 +1086,7 @@ mg_handle_form_request(struct mg_connection *conn,
+ if ((field_storage & MG_FORM_FIELD_STORAGE_ABORT)
+ == MG_FORM_FIELD_STORAGE_ABORT) {
+ /* Stop parsing the request */
++ abort_read = 1;
+ break;
+ }
+
+--
+2.47.3
+
diff -Nru civetweb-1.16+dfsg/debian/patches/CVE-2025-55763.patch
civetweb-1.16+dfsg/debian/patches/CVE-2025-55763.patch
--- civetweb-1.16+dfsg/debian/patches/CVE-2025-55763.patch 1970-01-01
02:00:00.000000000 +0200
+++ civetweb-1.16+dfsg/debian/patches/CVE-2025-55763.patch 2026-03-06
22:51:37.000000000 +0200
@@ -0,0 +1,86 @@
+From 76e222bcb77ba8452e5da4e82ae6cecd499c25e0 Mon Sep 17 00:00:00 2001
+From: krispybyte <[email protected]>
+Date: Sat, 21 Jun 2025 23:33:50 +0300
+Subject: [PATCH 1/2] Fix heap overflow in directory URI slash redirection
+
+---
+ src/civetweb.c | 23 ++++++++++++++++++-----
+ 1 file changed, 18 insertions(+), 5 deletions(-)
+
+Origin:
https://github.com/civetweb/civetweb/commit/c584455624d9a9f6ec72839f61dd3cdb9d8435ba.patch
+Bug: https://github.com/civetweb/civetweb/pull/1347
+
+diff --git a/src/civetweb.c b/src/civetweb.c
+index bbc9aa8be..e969c939f 100644
+--- a/src/civetweb.c
++++ b/src/civetweb.c
+@@ -15579,7 +15579,6 @@ handle_request(struct mg_connection *conn)
+ /* 12. Directory uris should end with a slash */
+ if (file.stat.is_directory && ((uri_len = (int)strlen(ri->local_uri)) >
0)
+ && (ri->local_uri[uri_len - 1] != '/')) {
+-
+ /* Path + server root */
+ size_t buflen = UTF8_PATH_MAX * 2 + 2;
+ char *new_path;
+@@ -15592,12 +15591,26 @@ handle_request(struct mg_connection *conn)
+ mg_send_http_error(conn, 500, "out or memory");
+ } else {
+ mg_get_request_link(conn, new_path, buflen - 1);
+- strcat(new_path, "/");
++
++ size_t len = strlen(new_path);
++ if (len + 1 < buflen) {
++ new_path[len] = '/';
++ new_path[len + 1] = '\0';
++ len += 1;
++ }
++
+ if (ri->query_string) {
+- /* Append ? and query string */
+- strcat(new_path, "?");
+- strcat(new_path, ri->query_string);
++ if (len + 1 < buflen) {
++ new_path[len] = '?';
++ new_path[len + 1] = '\0';
++ len += 1;
++ }
++
++ /* Append with size of space left for query
string + null terminator */
++ size_t max_append = buflen - len - 1;
++ strncat(new_path, ri->query_string, max_append);
+ }
++
+ mg_send_http_redirect(conn, new_path, 301);
+ mg_free(new_path);
+ }
+
+From d5321963b1d0bc953101de91f8588bf83db73bf5 Mon Sep 17 00:00:00 2001
+From: krispybyte <[email protected]>
+Date: Sun, 22 Jun 2025 00:23:06 +0300
+Subject: [PATCH 2/2] Fit code style
+
+---
+ src/civetweb.c | 4 ++--
+ 1 file changed, 2 insertions(+), 2 deletions(-)
+
+diff --git a/src/civetweb.c b/src/civetweb.c
+index e969c939f..6af91f874 100644
+--- a/src/civetweb.c
++++ b/src/civetweb.c
+@@ -15596,14 +15596,14 @@ handle_request(struct mg_connection *conn)
+ if (len + 1 < buflen) {
+ new_path[len] = '/';
+ new_path[len + 1] = '\0';
+- len += 1;
++ len++;
+ }
+
+ if (ri->query_string) {
+ if (len + 1 < buflen) {
+ new_path[len] = '?';
+ new_path[len + 1] = '\0';
+- len += 1;
++ len++;
+ }
+
+ /* Append with size of space left for query
string + null terminator */
diff -Nru civetweb-1.16+dfsg/debian/patches/series
civetweb-1.16+dfsg/debian/patches/series
--- civetweb-1.16+dfsg/debian/patches/series 2024-07-20 00:23:09.000000000
+0300
+++ civetweb-1.16+dfsg/debian/patches/series 2026-03-07 11:54:47.000000000
+0200
@@ -1,2 +1,4 @@
soversion
webdav-uploads
+CVE-2025-55763.patch
+0001-Make-parsing-of-URL-encoded-forms-more-robust.patch
