CVE-2023-4255 W3m: out-of-bounds write in function checktype() in etc.c (incomplete fix for cve-2022-38223)

What is CVE-2023-4255?

CVE-2023-4255 is a medium-severity memory corruption vulnerability in Fedoraproject Extra Packages for Enterprise Linux, published on 21 Dec 2023. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.

Official description

An out-of-bounds write issue has been discovered in the backspace handling of the checkType() function in etc.c within the W3M application. This vulnerability is triggered by supplying a specially crafted HTML file to the w3m binary. Exploitation of this flaw could lead to application crashes, resulting in a denial of service condition.

Weakness: CWE-787

Which versions are affected by CVE-2023-4255?

It affects 3 products.

Products include Fedoraproject Extra Packages for Enterprise Linux, Fedoraproject Fedora, Tats W3m.

How do I fix CVE-2023-4255?

Apply the vendor's patch.

Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.

Is CVE-2023-4255 being exploited?

There is no known exploitation of CVE-2023-4255 in the wild and no public exploit code.

Other vulnerabilities in Fedoraproject Extra Packages for Enterprise Linux

• CVE-2023-34152 Command injection in ImageMagick Critical 9.8
• CVE-2022-4170 Code injection in rxvt-unicode Critical 9.8
• CVE-2022-40315 Moodle Minor SQL injection risk in admin user browsing Critical 9.8
• CVE-2022-45152 Moodle blind Server-Side Request Forgery (SSRF) vulnerability in LTI provider library Critical 9.1
• CVE-2022-24882 Server side NTLM does not properly check parameters in FreeRDP Critical 9.1

All Fedoraproject Extra Packages for Enterprise Linux vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as DEBIAN-CVE-2023-4255, GHSA-hx3r-ph4g-9px9, SUSE-SU-2024:0014-1, UBUNTU-CVE-2023-4255, USN-6580-1.