Input validation error in ZNC - CVE-2024-39844

Vulnerability identifier: #VU97707

CSH Severity: High

CVSS v4: 8.5 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]

CVE-ID: CVE-2024-39844

CWE-ID: CWE-20

Exploitation vector: Remote access

Exploit availability: Public exploit is available

The vulnerability allows a remote user to compromise the affected system.

The vulnerability exists due to insufficient validation of user-supplied input in modtcl  when processing the reason to kick a user from the channel. A remote user can pass specially crafted input to the application and execute arbitrary code on the server.

ZNC
Debian Linux
Gentoo Linux
Fedora
Ubuntu
znc (Ubuntu package)
znc-dev (Ubuntu package)
znc-perl (Ubuntu package)
znc-python (Ubuntu package)
znc-tcl (Ubuntu package)
znc-clientbuffer
znc (Debian package)
znc
net-irc/znc
znc-push

Install updates from vendor's website.

ZNC - update to 1.9.1
znc (Ubuntu package) - addressed in versions Ubuntu Pro, 1.8.2-2ubuntu0.1
znc-dev (Ubuntu package) - addressed in versions Ubuntu Pro, 1.8.2-2ubuntu0.1
znc-perl (Ubuntu package) - addressed in versions Ubuntu Pro, 1.8.2-2ubuntu0.1
znc-python (Ubuntu package) - addressed in versions Ubuntu Pro, 1.8.2-2ubuntu0.1
znc-tcl (Ubuntu package) - addressed in versions Ubuntu Pro, 1.8.2-2ubuntu0.1
znc-clientbuffer - addressed in versions 0-0.28.20190129git9766a4a.fc41, 0-0.28.20190129git9766a4a.fc42
znc (Debian package) - addressed in versions 1.8.2-2+deb11u1, 1.8.2-3.1+deb12u1
znc - addressed in versions 1.8.2-16.el8, 1.8.2-16.el9, 1.9.1-4.fc41, 1.9.1-4.fc42
net-irc/znc - update to 1.9.1
znc-push - addressed in versions 2.0.0-10.20210311git4243934.fc41, 2.0.0-10.20210311git4243934.fc42

• Exploit #10896 - CVE-2024-39844 (November 22, 2024)

• https://wiki.znc.in/Category:ChangeLog
• https://github.com/znc/znc/releases/tag/znc-1.9.1
• https://wiki.znc.in/ChangeLog/1.9.1
• https://www.openwall.com/lists/oss-security/2024/07/03/9
• http://www.openwall.com/lists/oss-security/2024/07/03/9

• Remote code execution in ZNC
• Debian update for znc
• Ubuntu update for znc
• Gentoo update for ZNC
• Fedora 42 update for znc, znc-clientbuffer, znc-push
• Fedora 41 update for znc, znc-clientbuffer, znc-push
• Fedora EPEL 9 update for znc
• Fedora EPEL 8 update for znc