Vulnerability in Linux Kernel
CVE-2021-4159
A vulnerability was found in the Linux kernel's EBPF verifier when handling internal data structures. Internal memory locations could be returned to userspace. A local attacker with the permissions to insert eBPF code to the kernel can use this to leak internal kernel memory details defeating some of the exploit mitigations in place for the kernel.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 4.4 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:N/A:N.
EPSS exploit prediction
EPSS: 0.002 (14.3th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 14th percentile — 14.3% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.002 · newest: 0.002 · change: 0.000
Affected products
- Linux Kernel
- Debian Linux — versions 10.0
- Red Hat Enterprise Linux — versions 8.0
- Kernel — versions Fixed in v5.7-rc1
Weakness classification (CWE)
Public proof-of-concept exploits
References
- bugzilla.redhat.com/show_bug.cgi (Issue Tracking)
- access.redhat.com/security/cve/CVE-2021-4159 (Third Party Advisory)
- security-tracker.debian.org/tracker/CVE-2021-4159 (Third Party Advisory)
- git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/ (Patch, Mailing List, Vendor Advisory)
- lists.debian.org/debian-lts-announce/2022/10/msg00000.html (mailing-list, Mailing List, Third Party Advisory)
Frequently asked questions
- What is CVE-2021-4159?
- CVE-2021-4159 is a medium-severity vulnerability in Linux Kernel, classified under CWE-202. CVSS score: 4.4/10. Published 2022-08-24.
- How severe is CVE-2021-4159?
- Medium severity. CVSS v3 base score is 4.4 out of 10.
- Is CVE-2021-4159 known to be exploited?
- 2 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.