Bug#1007239: tightvnc: CVE-2022-23967 - overflow in vncviewer, possible duplicate report of CVE-2019-15679
Source: tightvnc
Version: 1:1.3.10-5
Severity: important
Tags: security
X-Debbugs-Cc: codehelp@debian.org, Debian Security Team <team@security.debian.org>
Hi,
The following vulnerability was published for tightvnc.
CVE-2022-23967[0]:
| In TightVNC 1.3.10, there is an integer signedness error and resultant
| heap-based buffer overflow in InitialiseRFBConnection in rfbproto.c
| (for the vncviewer component). There is no check on the size given to
| malloc, e.g., -1 is accepted. This allocates a chunk of size zero,
| which will give a heap pointer. However, one can send 0xffffffff bytes
| of data, which can have a DoS impact or lead to remote code execution.
Note: It seems plausible that the Debian patch for CVE-2019-15679
would also fix this new CVE as that patch does not appear in the
current upstream code referenced in the new CVE.
I have tried to reproduce the PoC for the new CVE in unstable but I
have been unable to get the PoC to work as described in the new CVE.
(The PoC requires some unpackaged Python modules, so a virtualenv
of some kind (or a test VM) would be needed.) In my test VM with
local changes for the PoC, the PoC script failed at line 24.
https://github.com/MaherAzzouzi/CVE-2022-23967/blob/main/poc.py
Please could you check if the patch for CVE-2019-15679 does indeed
fix the newly reported CVE?
If you fix the vulnerability please also make sure to include the
CVE (Common Vulnerabilities & Exposures) id in your changelog entry.
For further information see:
[0] https://security-tracker.debian.org/tracker/CVE-2022-23967
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2022-23967
Please adjust the affected versions in the BTS as needed.
-- System Information:
Debian Release: bookworm/sid
APT prefers unstable
APT policy: (500, 'unstable'), (1, 'experimental')
Architecture: amd64 (x86_64)
Foreign Architectures: i386
Kernel: Linux 5.16.0-4-amd64 (SMP w/16 CPU threads; PREEMPT)
Locale: LANG=en_GB.UTF-8, LC_CTYPE=en_GB.UTF-8 (charmap=UTF-8), LANGUAGE=en_GB:en
Shell: /bin/sh linked to /usr/bin/dash
Init: systemd (via /run/systemd/system)
LSM: AppArmor: enabled
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