CVE-2021-26930
What it is
An issue was discovered in the Linux kernel 3.11 through 5.10.16, as used by Xen. To service requests to the PV backend, the driver maps grant references provided by the frontend. In this process, errors may be encountered. In one case, an error encountered earlier might be discarded by later processing, resulting in the caller assuming successful mapping, and hence subsequent operations trying to access space that wasn't mapped. In another case, internal state would be insufficiently updated, preventing safe recovery from the error. This affects drivers/block/xen-blkback/blkback.c.
At a glance
- Exploitability
- Can be exploited locally on the machine with a low-privilege account. High risk of data exposure, data tampering, service disruption.
- Exploit odds
- 0.3% chance of exploitation in the next 30 days (EPSS).
- Fix
- A patch, advisory or fixed version is referenced. Upgrade or apply it.
Timeline
- PublishedDisclosed publicly on CVE.org and NVD
- Last updatedMost recent change to the record
Why it ranks here
- Exploited in the wild: no, CISA does not list it.
- Exploit odds: 0.3% in the next 30 days (EPSS).
- Severity: 7.8 HIGH (CVSS).
- Fix: a patch or advisory is linked.
Details
- Published
- Last modified
- Exploit probability
- 0.3% · EPSS, next 30 days
- Record status
- Modified
Affected
- Linux Kernel ≤ 5.10.16
- Fedoraproject Fedora 32
- Fedoraproject Fedora 33
- Debian Linux 9.0
Attack profile CVSS 3.1 · 7.8
- Attack vector
- Local
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Raw vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Is it in your code?
Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.
Read https://cve-list.com/agent/cve/CVE-2021-26930.md and follow it. Check whether this project is affected by CVE-2021-26930. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.
Fix and advisories
- http://xenbits.xen.org/xsa/advisory-365.html
- https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=871997bc9e423f05c7da7c9178e62dde5df2a7f8
- http://xenbits.xen.org/xsa/advisory-365.html
- https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=871997bc9e423f05c7da7c9178e62dde5df2a7f8
References
- http://xenbits.xen.org/xsa/advisory-365.html
- https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=871997bc9e423f05c7da7c9178e62dde5df2a7f8
- https://lists.debian.org/debian-lts-announce/2021/03/msg00010.html
- https://lists.debian.org/debian-lts-announce/2021/03/msg00035.html
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/2XQR52ICKRK3GC4HDWLMWF2U55YGAR63/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/GWQWPWYZRXVFJI5M3VCM72X27IB7CKOB/
- https://security.netapp.com/advisory/ntap-20210326-0001/
- http://xenbits.xen.org/xsa/advisory-365.html
- https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=871997bc9e423f05c7da7c9178e62dde5df2a7f8
- https://lists.debian.org/debian-lts-announce/2021/03/msg00010.html
- https://lists.debian.org/debian-lts-announce/2021/03/msg00035.html
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/2XQR52ICKRK3GC4HDWLMWF2U55YGAR63/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/GWQWPWYZRXVFJI5M3VCM72X27IB7CKOB/
- https://security.netapp.com/advisory/ntap-20210326-0001/