Vulnerability Description
The eBPF RINGBUF bpf_ringbuf_reserve() function in the Linux kernel did not check that the allocated size was smaller than the ringbuf size, allowing an attacker to perform out-of-bounds writes within the kernel and therefore, arbitrary code execution. This issue was fixed via commit 4b81ccebaeee ("bpf, ringbuf: Deny reserve of buffers larger than ringbuf") (v5.13-rc4) and backported to the stable kernels in v5.12.4, v5.11.21, and v5.10.37. It was introduced via 457f44363a88 ("bpf: Implement BPF ring buffer and verifier support for it") (v5.8-rc1).
CVSS Score
HIGH
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Linux | Linux Kernel | >= 5.8, < 5.10.37 |
| Canonical | Ubuntu Linux | 20.04 |
Related Weaknesses (CWE)
References
- https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf.git/commit/?id=4b81ccebaPatchVendor Advisory
- https://security.netapp.com/advisory/ntap-20210716-0004/Third Party Advisory
- https://ubuntu.com/security/notices/USN-4949-1Third Party Advisory
- https://ubuntu.com/security/notices/USN-4950-1Third Party Advisory
- https://www.openwall.com/lists/oss-security/2021/05/11/10Mailing ListThird Party Advisory
- https://www.zerodayinitiative.com/advisories/ZDI-21-590/Third Party AdvisoryVDB Entry
- https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf.git/commit/?id=4b81ccebaPatchVendor Advisory
- https://security.netapp.com/advisory/ntap-20210716-0004/Third Party Advisory
- https://ubuntu.com/security/notices/USN-4949-1Third Party Advisory
- https://ubuntu.com/security/notices/USN-4950-1Third Party Advisory
- https://www.openwall.com/lists/oss-security/2021/05/11/10Mailing ListThird Party Advisory
- https://www.zerodayinitiative.com/advisories/ZDI-21-590/Third Party AdvisoryVDB Entry
FAQ
What is CVE-2021-3489?
CVE-2021-3489 is a vulnerability with a CVSS score of 7.8 (HIGH). The eBPF RINGBUF bpf_ringbuf_reserve() function in the Linux kernel did not check that the allocated size was smaller than the ringbuf size, allowing an attacker to perform out-of-bounds writes within...
How severe is CVE-2021-3489?
CVE-2021-3489 has been rated HIGH with a CVSS base score of 7.8/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2021-3489?
Check the references section above for vendor advisories and patch information. Affected products include: Linux Linux Kernel, Canonical Ubuntu Linux.