CVE-2023-42116

NameCVE-2023-42116
DescriptionExim SMTP Challenge Stack-based Buffer Overflow Remote Code Execution Vulnerability. This vulnerability allows remote attackers to execute arbitrary code on affected installations of Exim. Authentication is not required to exploit this vulnerability. The specific flaw exists within the handling of NTLM challenge requests. The issue results from the lack of proper validation of the length of user-supplied data prior to copying it to a fixed-length stack-based buffer. An attacker can leverage this vulnerability to execute code in the context of the service account. Was ZDI-CAN-17515.
SourceCVE (at NVD; CERT, LWN, oss-sec, fulldisc, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)
ReferencesDLA-3599-1, DSA-5512-1

Vulnerable and fixed packages

The table below lists information on source packages.

Source PackageReleaseVersionStatus
exim4 (PTS)buster4.92-8+deb10u6vulnerable
buster (security)4.92-8+deb10u9fixed
bullseye (security), bullseye4.94.2-7+deb11u2fixed
bookworm, bookworm (security)4.96-15+deb12u4fixed
sid, trixie4.97-8fixed

The information below is based on the following data on fixed versions.

PackageTypeReleaseFixed VersionUrgencyOriginDebian Bugs
exim4sourcebuster4.92-8+deb10u8DLA-3599-1
exim4sourcebullseye4.94.2-7+deb11u1DSA-5512-1
exim4sourcebookworm4.96-15+deb12u2DSA-5512-1
exim4source(unstable)4.97~RC1-2

Notes

https://www.zerodayinitiative.com/advisories/ZDI-23-1470/
https://bugs.exim.org/show_bug.cgi?id=3000
https://git.exim.org/exim.git/log/refs/heads/exim-4.96%20security/exim.git/commit/936e342d560e218c2aee5cb2295be925c27c2106
https://www.openwall.com/lists/oss-security/2023/09/29/5
https://www.openwall.com/lists/oss-security/2023/10/01/4
https://exim.org/static/doc/security/CVE-2023-zdi.txt

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