The Linux kernel 2.6.20 and 2.6.21 does not properly handle an invalid LDT segment…
Priority LOW 23CWE-20Published · Updated
Key facts
- Attack vector
- Local
- Privileges required
- None
- User interaction
- — Not recorded in CVSS 2.0
- Attack complexity
- Low
- Impact type
- —
- Confidentiality · integrity · availability
- None · None · Complete
- Fix status
- Fixed
Attack profile from CVSS 2.0 · NVD. Fix status from CNA and Red Hat.
Summary
The Linux kernel 2.6.20 and 2.6.21 does not properly handle an invalid LDT segment selector in %cs (the xcs field) during ptrace single-step operations, which allows local users to cause a denial of service (NULL dereference and OOPS) via certain code that makes ptrace PTRACE_SETREGS and PTRACE_SINGLESTEP requests, related to the TRACE_IRQS_ON function, and possibly related to the arch_ptrace function.
Why it matters now
EPSS 0.00512 43rd percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by NVD
Fix Fixed Red Hat: 1 advisory
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| — | — | all versions | — | No fix listed | CNA |
- — Vendor— Affected all versions Fixed in — No fix listed CNA
Remediation
Red Hat 1 advisory
- RHSA-2007:0940 Released 2007-10-22 · Red Hat rating Importantkernel security update
- Red Hat Enterprise Linux (v. 5 server) kernel-2.6.18-8.1.15.el5, kernel-2.6.18-8.1.15.el5.ia64, kernel-PAE-2.6.18-8.1.15.el5 +10
- Red Hat Enterprise Linux Desktop (v. 5 client) kernel-2.6.18-8.1.15.el5, kernel-PAE-2.6.18-8.1.15.el5, kernel-PAE-devel-2.6.18-8.1.15.el5 +4
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux (v. 5 server) | Fixed | RHSA-2007:0940 |
| Red Hat Enterprise Linux Desktop (v. 5 client) | Fixed | RHSA-2007:0940 |
Timeline
- 2026-10-02 Threatist record created from CVE-2007-3731
- 2026-10-03 Alias added: GHSA-frx9-99ch-7q7j
References
Advisory 3
Other 6
- http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git%3Ba=commitdiff%3Bh=a10d9a71bafd3a283da240d2868e71346d2aef6f
- 37286
- http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git%3Ba=commitdiff%3Bh=29eb51101c02df517ca64ec472d7501127ad1da8
- http://wiki.rpath.com/wiki/Advisories:rPSA-2008-0094
- https://issues.rpath.com/browse/RPL-2304
- oval:org.mitre.oval:def:10394
More Linux Kernel vulnerabilities
- TI-2025-26358 tls: fix handling of zero-length records on the rx_list KEVCVSS 3.1CRITICAL 9.8
- TI-2026-38352 netfilter: bridge: make ebt_snat ARP rewrite writable KEVCVSS 3.1HIGH 8.8
- TI-2013-05264 The (1) get_user and (2) put_user API functions in the Linux kernel before 3.5.5 on the… KEVCVSS 3.1HIGH 8.8
- TI-2022-00125 Integer overflow in kernel KEVCVSS 3.1HIGH 8.4
- TI-2013-01864 The perf_swevent_init function in kernel/events/core.c in the Linux kernel before 3.8.9… KEVCVSS 3.1HIGH 8.4
- TI-2021-05514 Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACE KEVCVSS 3.1HIGH 8.3
Sources
- CVE-2007-3731 · CVE Program
- CVE-2007-3731 · NVD
- FIRST EPSS
- GHSA-frx9-99ch-7q7j · GitHub Advisory Database · CC BY 4.0
- CVE-2007-3731 · Red Hat security data · CC BY 4.0
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