Use After Free in Linux Kernel
CVE-2020-29569
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.
Vulnerability class: Use-After-Free
Published · last modified .
CVSS v3 metric
CVSS v3 base score 8.8 (High). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H.
EPSS exploit prediction
EPSS: 0.004 (33.9th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 34th percentile — 33.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.004 · newest: 0.004 · change: +0.000
Affected products
Weakness classification (CWE)
References
- xenbits.xenproject.org/xsa/advisory-350.html (Patch, Vendor Advisory)
- www.debian.org/security/2021/dsa-4843 (vendor-advisory, Third Party Advisory)
- security.netapp.com/advisory/ntap-20210205-0001/ (Third Party Advisory)
- lists.debian.org/debian-lts-announce/2021/02/msg00018.html (mailing-list, Mailing List, Third Party Advisory)
- lists.debian.org/debian-lts-announce/2021/03/msg00010.html (mailing-list, Mailing List, Third Party Advisory)
- security.gentoo.org/glsa/202107-30 (vendor-advisory, Third Party Advisory)
Frequently asked questions
- What is CVE-2020-29569?
- CVE-2020-29569 is a high-severity vulnerability in Linux Kernel, classified under Use After Free. CVSS score: 8.8/10. Published 2020-12-15.
- How severe is CVE-2020-29569?
- High severity. CVSS v3 base score is 8.8 out of 10.