Vulnerability Description
Kernel Samepage Merging (KSM) in the Linux kernel 2.6.32 through 4.x does not prevent use of a write-timing side channel, which allows guest OS users to defeat the ASLR protection mechanism on other guest OS instances via a Cross-VM ASL INtrospection (CAIN) attack. NOTE: the vendor states "Basically if you care about this attack vector, disable deduplication." Share-until-written approaches for memory conservation among mutually untrusting tenants are inherently detectable for information disclosure, and can be classified as potentially misunderstood behaviors rather than vulnerabilities
CVSS Score
LOW
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Linux | Linux Kernel | >= 2.6.32, <= 4.20.15 |
| Redhat | Enterprise Linux | 4.0 |
Related Weaknesses (CWE)
References
- http://www.antoniobarresi.com/files/cain_advisory.txtTechnical DescriptionThird Party Advisory
- http://www.kb.cert.org/vuls/id/935424Third Party AdvisoryUS Government Resource
- http://www.securityfocus.com/bid/76256Third Party AdvisoryVDB Entry
- https://bugzilla.redhat.com/show_bug.cgi?id=1252096Issue TrackingThird Party Advisory
- https://www.kb.cert.org/vuls/id/BGAR-A2CNKGThird Party AdvisoryUS Government Resource
- https://www.kb.cert.org/vuls/id/BLUU-9ZAHZHThird Party AdvisoryUS Government Resource
- https://www.usenix.org/system/files/conference/woot15/woot15-paper-barresi.pdfTechnical DescriptionThird Party Advisory
- http://www.antoniobarresi.com/files/cain_advisory.txtTechnical DescriptionThird Party Advisory
- http://www.kb.cert.org/vuls/id/935424Third Party AdvisoryUS Government Resource
- http://www.securityfocus.com/bid/76256Third Party AdvisoryVDB Entry
- https://bugzilla.redhat.com/show_bug.cgi?id=1252096Issue TrackingThird Party Advisory
- https://www.kb.cert.org/vuls/id/BGAR-A2CNKGThird Party AdvisoryUS Government Resource
- https://www.kb.cert.org/vuls/id/BLUU-9ZAHZHThird Party AdvisoryUS Government Resource
- https://www.usenix.org/system/files/conference/woot15/woot15-paper-barresi.pdfTechnical DescriptionThird Party Advisory
FAQ
What is CVE-2015-2877?
CVE-2015-2877 is a vulnerability with a CVSS score of 3.3 (LOW). Kernel Samepage Merging (KSM) in the Linux kernel 2.6.32 through 4.x does not prevent use of a write-timing side channel, which allows guest OS users to defeat the ASLR protection mechanism on other g...
How severe is CVE-2015-2877?
CVE-2015-2877 has been rated LOW with a CVSS base score of 3.3/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2015-2877?
Check the references section above for vendor advisories and patch information. Affected products include: Linux Linux Kernel, Redhat Enterprise Linux.