Control: tags 1118285 + patch Control: tags 1118285 + pending Dear maintainer,
I've prepared an NMU for civetweb (versioned as 1.16+dfsg-3.1) and uploaded it to DELAYED/2. Please feel free to tell me if I should cancel it. cu Adrian
diffstat for civetweb-1.16+dfsg civetweb-1.16+dfsg changelog | 8 patches/0001-Make-parsing-of-URL-encoded-forms-more-robust.patch | 246 ++++++++++ patches/series | 1 3 files changed, 255 insertions(+) diff -Nru civetweb-1.16+dfsg/debian/changelog civetweb-1.16+dfsg/debian/changelog --- civetweb-1.16+dfsg/debian/changelog 2025-09-27 02:10:04.000000000 +0300 +++ civetweb-1.16+dfsg/debian/changelog 2026-03-04 18:59:54.000000000 +0200 @@ -1,3 +1,11 @@ +civetweb (1.16+dfsg-3.1) unstable; urgency=medium + + * Non-maintainer upload. + * CVE-2025-9648: Infinite loop in mg_handle_form_request + (Closes: #1118285) + + -- Adrian Bunk <[email protected]> Wed, 04 Mar 2026 18:59:54 +0200 + civetweb (1.16+dfsg-3) unstable; urgency=medium * Team upload. 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 2026-03-04 18:59:54.000000000 +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/series civetweb-1.16+dfsg/debian/patches/series --- civetweb-1.16+dfsg/debian/patches/series 2025-09-27 02:09:29.000000000 +0300 +++ civetweb-1.16+dfsg/debian/patches/series 2026-03-04 18:59:54.000000000 +0200 @@ -1,3 +1,4 @@ soversion webdav-uploads CVE-2025-55763.patch +0001-Make-parsing-of-URL-encoded-forms-more-robust.patch
