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CVE-2018-18281

UnknownEPSS 1.06%

Last modified

CVE-2018-18281 is a vulnerability of currently unknown severity. Since Linux kernel version 3.2, the mremap() syscall performs TLB flushes after dropping pagetable locks. If a syscall such as ftruncate() removes entries from the pagetables of a task that is in the middle of mremap(), a stale TLB entry can remain for a short time that permits access to a physical page after it has been released back to the page allocator and reused. EPSS estimates a 1.06% chance of exploitation in the next 30 days.

Description

Since Linux kernel version 3.2, the mremap() syscall performs TLB flushes after dropping pagetable locks. If a syscall such as ftruncate() removes entries from the pagetables of a task that is in the middle of mremap(), a stale TLB entry can remain for a short time that permits access to a physical page after it has been released back to the page allocator and reused. This is fixed in the following kernel versions: 4.9.135, 4.14.78, 4.18.16, 4.19.

Metrics

EPSS Probability
1.06%

60.3th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

VendorProductVersions
LinuxLinux Kernel>= 3.2, < 4.9.135
LinuxLinux Kernel>= 4.9.136, < 4.14.78
LinuxLinux Kernel>= 4.14.79, < 4.18.16
LinuxLinux Kernel>= 4.18.17, < 4.19
CanonicalUbuntu Linux12.04
CanonicalUbuntu Linux14.04
CanonicalUbuntu Linux16.04
CanonicalUbuntu Linux18.04
CanonicalUbuntu Linux18.10
DebianDebian Linux8.0

References

Timeline

Published
Last Modified
Status
Modified

Frequently Asked Questions

What is CVE-2018-18281?
Since Linux kernel version 3.2, the mremap() syscall performs TLB flushes after dropping pagetable locks. If a syscall such as ftruncate() removes entries from the pagetables of a task that is in the middle of mremap(), a stale TLB entry can remain for a short time that permits access to a physical page after it has been released back to the page allocator and reused. This is fixed in the following kernel versions: 4.9.135, 4.14.78, 4.18.16, 4.19.
How severe is CVE-2018-18281?
Severity scoring for CVE-2018-18281 is pending analysis. The EPSS model estimates a 1.06% probability of exploitation in the next 30 days.
How do I fix CVE-2018-18281?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2018-18281?

Run a free Strix scan to check your systems for this vulnerability.

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Source: NVD / NIST