diff options
| author | Peter Kaestle <peter.kaestle@nokia.com> | 2021-03-15 13:19:56 +0100 |
|---|---|---|
| committer | Matt Caswell <matt@openssl.org> | 2021-03-25 09:43:33 +0000 |
| commit | fb9fa6b51defd48157eeb207f52181f735d96148 (patch) | |
| tree | b368186caf503654d25ccfcae34f46893f360a89 | |
| parent | 3ff38629a2df6635f36bfb79513cc6440db8cd70 (diff) | |
ssl sigalg extension: fix NULL pointer dereference
As the variable peer_sigalgslen is not cleared on ssl rehandshake, it's
possible to crash an openssl tls secured server remotely by sending a
manipulated hello message in a rehandshake.
On such a manipulated rehandshake, tls1_set_shared_sigalgs() calls
tls12_shared_sigalgs() with the peer_sigalgslen of the previous
handshake, while the peer_sigalgs has been freed.
As a result tls12_shared_sigalgs() walks over the available
peer_sigalgs and tries to access data of a NULL pointer.
This issue was introduced by c589c34e61 (Add support for the TLS 1.3
signature_algorithms_cert extension, 2018-01-11).
Signed-off-by: Peter Kästle <peter.kaestle@nokia.com>
Signed-off-by: Samuel Sapalski <samuel.sapalski@nokia.com>
CVE-2021-3449
CLA: trivial
Reviewed-by: Tomas Mraz <tomas@openssl.org>
Reviewed-by: Paul Dale <pauli@openssl.org>
Reviewed-by: Matt Caswell <matt@openssl.org>
| -rw-r--r-- | ssl/statem/extensions.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/ssl/statem/extensions.c b/ssl/statem/extensions.c index b055935d69..4aed508d0f 100644 --- a/ssl/statem/extensions.c +++ b/ssl/statem/extensions.c @@ -1139,6 +1139,7 @@ static int init_sig_algs(SSL *s, unsigned int context) /* Clear any signature algorithms extension received */ OPENSSL_free(s->s3->tmp.peer_sigalgs); s->s3->tmp.peer_sigalgs = NULL; + s->s3->tmp.peer_sigalgslen = 0; return 1; } |