From 8e5ca951257202089246fa37e93a99d210ee5ca2 Mon Sep 17 00:00:00 2001 From: Andrew Hamilton Date: Mon, 7 Jul 2025 10:23:59 +0900 Subject: [PATCH] x509: fix read buffer overrun in SCT timestamps Prevent reading beyond heap buffer in call to _gnutls_parse_ct_sct when processing x509 Signed Certificate Timestamps with certain malformed data. Spotted by oss-fuzz at: https://issues.oss-fuzz.com/issues/42530513 Signed-off-by: Andrew Hamilton Signed-off-by: Daiki Ueno CVE: CVE-2025-32989 Upstream-Status: Backport [https://gitlab.com/gnutls/gnutls/-/commit/8e5ca951257202089246fa37e93a99d210ee5ca2] Signed-off-by: Peter Marko --- NEWS | 5 +++++ lib/x509/x509_ext.c | 2 +- 2 files changed, 6 insertions(+), 1 deletion(-) diff --git a/NEWS b/NEWS index 85efb5680..025e05148 100644 --- a/NEWS +++ b/NEWS @@ -5,6 +5,11 @@ Copyright (C) 2000-2016 Free Software Foundation, Inc. Copyright (C) 2013-2019 Nikos Mavrogiannopoulos See the end for copying conditions. +** libgnutls: Fix heap read buffer overrun in parsing X.509 SCTS timestamps + Spotted by oss-fuzz and reported by OpenAI Security Research Team, + and fix developed by Andrew Hamilton. [GNUTLS-SA-2025-07-07-1, + CVSS: medium] [CVE-2025-32989] + * Version 3.8.4 (released 2024-03-18) ** libgnutls: RSA-OAEP encryption scheme is now supported diff --git a/lib/x509/x509_ext.c b/lib/x509/x509_ext.c index 064ca8357..05336a0c2 100644 --- a/lib/x509/x509_ext.c +++ b/lib/x509/x509_ext.c @@ -3757,7 +3757,7 @@ int gnutls_x509_ext_ct_import_scts(const gnutls_datum_t *ext, } length = _gnutls_read_uint16(scts_content.data); - if (length < 4) { + if (length < 4 || length > scts_content.size) { gnutls_free(scts_content.data); return GNUTLS_E_REQUESTED_DATA_NOT_AVAILABLE; }