From 97c62c6167299028d80765080e74d91dfc99efbd Mon Sep 17 00:00:00 2001 From: Simo Sorce Date: Tue, 7 Feb 2023 13:51:34 -0500 Subject: [PATCH] Out-of-bounds read in multiple decode functions These were reported as: - Out-of-bounds read in ntlm_decode_oem_str (GHSL-2023-019) - Out-of-bounds read in ntlm_decode_u16l_str_hdr (GHSL-2023-020) - Out-of-bounds read in ntlm_decode_field (GHSL-2023-021) These are lall basically the same identical error replicated in 3 separate functions. Fixes defects GHSL-2023-019, GHSL-2023-020, GHSL-2023-021 found by the GitHub Security Lab team via oss-fuzz. A 32-bit integer overflow condition can lead to incorrect checks of consistency of length of internal buffers. This leads to a DoS as the service may end up reading from unmapped memory and crashing. Although most applications will error out before accepting a singe input buffer of 4GB in lenght this could theoretically happen, and therefore we fix it. Fixes CVE-2023-25563 Signed-off-by: Simo Sorce --- src/ntlm.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/src/ntlm.c b/src/ntlm.c index b2d84a2..df2458a 100644 --- a/src/ntlm.c +++ b/src/ntlm.c @@ -205,7 +205,6 @@ static int ntlm_str_convert(iconv_t cd, return 0; } - uint8_t ntlmssp_sig[8] = {'N', 'T', 'L', 'M', 'S', 'S', 'P', 0}; static void ntlm_encode_header(struct wire_msg_hdr *hdr, uint32_t msg_type) @@ -256,6 +255,7 @@ static int ntlm_decode_oem_str(struct wire_field_hdr *str_hdr, str_offs = le32toh(str_hdr->offset); if ((str_offs < payload_offs) || (str_offs > buffer->length) || + (UINT32_MAX - str_offs < str_len) || (str_offs + str_len > buffer->length)) { return ERR_DECODE; } @@ -308,6 +308,7 @@ static int ntlm_decode_u16l_str_hdr(struct ntlm_ctx *ctx, str_offs = le32toh(str_hdr->offset); if ((str_offs < payload_offs) || (str_offs > buffer->length) || + (UINT32_MAX - str_offs < str_len) || (str_offs + str_len > buffer->length)) { return ERR_DECODE; } @@ -393,6 +394,7 @@ static int ntlm_decode_field(struct wire_field_hdr *hdr, offs = le32toh(hdr->offset); if ((offs < payload_offs) || (offs > buffer->length) || + (UINT32_MAX - offs < len) || (offs + len > buffer->length)) { return ERR_DECODE; }