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0dc820fe1d
The buffer we pass to tls_crypt_v2_extract_client_key contains the
entire received control channel packet. We should skip the opcode before
trying to read WKC.
This logic error is a second bug behind the XlabAI finding, next too the
too-strict ASSERT in tls_crypt_unwrap.
Also remove a too strict ASSERT in tls_crypt_unwrap. We already check
a few lines later for a too short packet and return a proper error
("packet too short").
XlabAI found a way of triggering this ASSERT that requires a tls-crypt-v2
client key that has a specific property (a specific byte need to have a
specific value, about 1/256 probability). If an attacker can get hold of
such a tls-crypt-v2 client key or observe a handshake using such a key,
the attacker can trigger the ASSERT, crashing the server. Setups that do
not use tls-crypt-v2 are not affected.
Independently, Cisco Talos reported a way to trigger this ASSERT with any
tls-crypt-v2 key but this requires the attacker to be also in possession
of the private key part of the tls-crypt-v2 client key or to inject packet
into a live session of a client session.
CVE: 2026-35058
Reported-By: XlabAI Team of Tencent Xuanwu Lab (xlabai@tencent.com)
Reported-By: Guannan Wang (wgnbuaa@gmail.com
Reported-By: Zhanpeng Liu (pkugenuine@gmail.com)
Reported-By: Guancheng Li (lgcpku@gmail.com)
Reported-By: Emma Reuter of Cisco ASIG (TALOS-2026-2381)
Signed-off-by: Steffan Karger <steffan@karger.me>
Signed-off-by: Arne Schwabe <arne@rfc2549.org>
Change-Id: I623733c0476c98f436d19009ee8990693c1579b5
Private-URL: https://github.com/OpenVPN/openvpn-private-issues/issues/111
Acked-by: Gert Doering <gert@greenie.muc.de>
Signed-off-by: Gert Doering <gert@greenie.muc.de>
(cherry picked from commit 18270324a5fd43122ca1b8c29b224c5dd5905429)
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| unit_tests | ||
| Makefile.am | ||
| ntlm_support.c | ||
| t_client.rc-sample | ||
| t_client.sh.in | ||
| t_cltsrv-down.sh | ||
| t_cltsrv.sh | ||
| t_lpback.sh | ||
| t_net.sh | ||
| update_t_client_ips.sh | ||