CVE-2020-29569
What it is
An issue was discovered in the Linux kernel through 5.10.1, as used with Xen through 4.14.x. The Linux kernel PV block backend expects the kernel thread handler to reset ring->xenblkd to NULL when stopped. However, the handler may not have time to run if the frontend quickly toggles between the states connect and disconnect. As a consequence, the block backend may re-use a pointer after it was freed. A misbehaving guest can trigger a dom0 crash by continuously connecting / disconnecting a block frontend. Privilege escalation and information leaks cannot be ruled out. This only affects systems with a Linux blkback.
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
- 0.4% 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: 0.4% in the next 30 days (EPSS).
- Severity: 8.8 HIGH (CVSS).
- Fix: a patch or advisory is linked.
Details
- Published
- Last modified
- Exploit probability
- 0.4% · EPSS, next 30 days
- Weakness
- CWE-416 · Use after free
- Record status
- Modified
Affected
- Xen ≤ 4.14.1
- Linux Kernel < 4.2
- Linux Kernel < 4.4.254
- Linux Kernel < 4.9.249
- Linux Kernel < 4.12
- Linux Kernel < 4.14.213
- Linux Kernel < 4.19.164
- Linux Kernel < 5.4.86
Attack profile CVSS 3.1 · 8.8
- Attack vector
- Local
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- None
- Scope
- Changed
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Raw vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/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-2020-29569.md and follow it. Check whether this project is affected by CVE-2020-29569. 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
- https://xenbits.xenproject.org/xsa/advisory-350.html
- https://xenbits.xenproject.org/xsa/advisory-350.html
References
- https://lists.debian.org/debian-lts-announce/2021/02/msg00018.html
- https://lists.debian.org/debian-lts-announce/2021/03/msg00010.html
- https://security.gentoo.org/glsa/202107-30
- https://security.netapp.com/advisory/ntap-20210205-0001/
- https://www.debian.org/security/2021/dsa-4843
- https://xenbits.xenproject.org/xsa/advisory-350.html
- https://lists.debian.org/debian-lts-announce/2021/02/msg00018.html
- https://lists.debian.org/debian-lts-announce/2021/03/msg00010.html
- https://security.gentoo.org/glsa/202107-30
- https://security.netapp.com/advisory/ntap-20210205-0001/
- https://www.debian.org/security/2021/dsa-4843
- https://xenbits.xenproject.org/xsa/advisory-350.html