CVE-2023-3773 Kernel: xfrm: out-of-bounds read of xfrma_mtimer_thresh nlattr

What is CVE-2023-3773?

CVE-2023-3773 is a medium-severity vulnerability in Debian Debian Linux, published on 25 Jul 2023. It can only be exploited from the same machine or local network, with no action from the victim.

Official description

A flaw was found in the Linux kernel’s IP framework for transforming packets (XFRM subsystem). This issue may allow a malicious user with CAP_NET_ADMIN privileges to cause a 4 byte out-of-bounds read of XFRMA_MTIMER_THRESH when parsing netlink attributes, leading to potential leakage of sensitive heap data to userspace.

Weakness: CWE-125

Which versions are affected by CVE-2023-3773?

It affects 4 products.

Products include Debian Debian Linux, Fedoraproject Fedora, Linux kernel, Redhat Enterprise Linux.

How do I fix CVE-2023-3773?

Apply the vendor's patch.

Is CVE-2023-3773 being exploited?

There is no known exploitation of CVE-2023-3773 in the wild and no public exploit code.

Other vulnerabilities in Debian Debian Linux

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• CVE-2025-49113 RoundCube Webmail Deserialization of Untrusted Data Exploited Critical 9.9
• CVE-2026-24061 GNU InetUtils Argument Injection Exploited Critical 9.8
• CVE-2025-39682 Linux Kernel Improper Check for Unusual or Exceptional Conditions Exploited Critical 9.8
• CVE-2024-9680 Mozilla Firefox Use-After-Free Exploited Critical 9.8

All Debian Debian Linux vulnerabilities

Sources

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

Also known as AZL-33496, DEBIAN-CVE-2023-3773, GHSA-2m35-m4g6-x835, UBUNTU-CVE-2023-3773.