Kernel-memory disclosure via unchecked XFRM prefix lengths
Published Oct 9, 2023 · Updated Nov 6, 2025
Out-of-bounds read in the Linux kernel XFRM subsystem on Red Hat Enterprise Linux 8 and 9 allows local users to disclose kernel memory. xfrm_dump_sa() copies attacker-controlled splen and dplen prefix lengths from an XFRM address filter without validating their bounds, causing memcmp() to read eight bytes beyond the allocated filter. Exploitation requires CAP_NET_ADMIN and a crafted XFRM state-dump request; the documented direct consequence is disclosure of adjacent kernel heap data.
Summary
What happened
Out-of-bounds read in the Linux kernel XFRM subsystem on Red Hat Enterprise Linux 8 and 9 allows local users to disclose kernel memory. xfrm_dump_sa() copies attacker-controlled splen and dplen prefix lengths from an XFRM address filter without validating their bounds, causing memcmp() to read eight bytes beyond the allocated filter. Exploitation requires CAP_NET_ADMIN and a crafted XFRM state-dump request; the documented direct consequence is disclosure of adjacent kernel heap data.
The record
- CVE
- CVE-2023-39194
- Published
- Oct 9, 2023
- Updated
- Nov 6, 2025
- Vendor
- Red Hat
- Product
- Red Hat Enterprise Linux 8
- Classifications
- CWE-125
- Attack vector
- local
- Privileges
- admin
Timeline
How it unfolded
- Oct 9, 2023CVE publishedPublication date reported by the CVE source.
- Nov 6, 2025Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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What conditions does exploitation require?
What is affected?
Attacks
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Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
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Your stack
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