What’s Vulnerable › Vulnerabilities
CVE-2020-27170
- Severity: medium (CVSS 4.7 v3.1)
- Exploited in the wild: not listed in CISA KEV
- EPSS: 0.6% probability of exploitation in the next 30 days
- Public exploit or detection template: none known
- Published: 2021-03-20 · updated 2026-10-08
- Weakness: CWE-203
Description
An issue was discovered in the Linux kernel before 5.11.8. kernel/bpf/verifier.c performs undesirable out-of-bounds speculation on pointer arithmetic, leading to side-channel attacks that defeat Spectre mitigations and obtain sensitive information from kernel memory, aka CID-f232326f6966. This affects pointer types that do not define a ptr_limit.
Affected products
- Canonical Ubuntu Linux: 14.04, 16.04, 18.04, 20.04
- Debian Linux: 9.0
- Fedoraproject Fedora: 32, 33, 34
- Linux kernel: before 5.11.8 — fixed in 5.11.8
How to fix
Upgrade to a fixed version: Linux kernel 5.11.8. Check the vendor advisory for mitigations.
References
- http://packetstormsecurity.com/files/162117/Kernel-Live-Patch-Security-Notice-LSN-0075-1.html
- http://www.openwall.com/lists/oss-security/2021/03/24/4
- https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.11.8
- https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=f232326f6966cf2a1d1db7bc917a4ce5f9f55f76
- https://lists.debian.org/debian-lts-announce/2021/03/msg00035.html
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/FB6LUXPEIRLZH32YXWZVEZAD4ZL6SDK2/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/QRTPQE73ANG7D6M4L4PK5ZQDPO4Y2FVD/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/T2S3I4SLRNRUQDOFYUS6IUAZMQNMPNLG/
- https://www.openwall.com/lists/oss-security/2021/03/19/2
- http://packetstormsecurity.com/files/162117/Kernel-Live-Patch-Security-Notice-LSN-0075-1.html
- http://www.openwall.com/lists/oss-security/2021/03/24/4
- https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.11.8
Get alerted when CVE-2020-27170 or the next vulnerability affects your stack