How severe is CVE-2007-3731?

CVE-2007-3731 has a CVSS 2.0 base score of 4.9, rated medium severity.

Is CVE-2007-3731 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (40th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2007-3731?

CVE-2007-3731 primarily affects Linux Linux Kernel. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2007-3731?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2007-3731 published?

CVE-2007-3731 was published on 2007-09-17 and last updated on 2026-06-16.

CVE-2007-3731

CVE-2007-3731 is a medium-severity vulnerability in Linux Linux Kernel with a CVSS 2.0 base score of 4.9. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-20.

Key facts

Severity: Medium (CVSS 2.0 base score 4.9)
EPSS exploit prediction: 1% (40th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-20
Affected product: Linux Linux Kernel
Published: 2007-09-17
Last modified: 2026-06-16

Description

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.

Frequently asked questions

What is CVE-2007-3731?: 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.
How severe is CVE-2007-3731?: CVE-2007-3731 has a CVSS 2.0 base score of 4.9, rated medium severity.
Is CVE-2007-3731 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (40th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2007-3731?: CVE-2007-3731 primarily affects Linux Linux Kernel. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2007-3731?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2007-3731 published?: CVE-2007-3731 was published on 2007-09-17 and last updated on 2026-06-16.

References

Affected products (2)

cpe:2.3:o:linux:linux_kernel:2.6.20:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:2.6.21:*:*:*:*:*:*:*

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