Out-of-Bounds The advisory has been revoked - it doesn't affect any version of package kernel-debug-modules-extra (opens in a new tab)
Threat Intelligence
Snyk has a proof-of-concept or detailed explanation of how to exploit this vulnerability.
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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Test your applications- Snyk IDSNYK-CENTOS8-KERNELDEBUGMODULESEXTRA-1965754
- published26 Jul 2021
- disclosed11 May 2021
Introduced: 11 May 2021
CVE-2021-3490 (opens in a new tab)Amendment
The Centos security team deemed this advisory irrelevant for Centos:8.
NVD Description
Note: Versions mentioned in the description apply only to the upstream kernel-debug-modules-extra package and not the kernel-debug-modules-extra package as distributed by Centos.
The eBPF ALU32 bounds tracking for bitwise ops (AND, OR and XOR) in the Linux kernel did not properly update 32-bit bounds, which could be turned into out of bounds reads and writes in the Linux kernel and therefore, arbitrary code execution. This issue was fixed via commit 049c4e13714e ("bpf: Fix alu32 const subreg bound tracking on bitwise operations") (v5.13-rc4) and backported to the stable kernels in v5.12.4, v5.11.21, and v5.10.37. The AND/OR issues were introduced by commit 3f50f132d840 ("bpf: Verifier, do explicit ALU32 bounds tracking") (5.7-rc1) and the XOR variant was introduced by 2921c90d4718 ("bpf:Fix a verifier failure with xor") ( 5.10-rc1).
References
- https://security.netapp.com/advisory/ntap-20210716-0004/
- https://access.redhat.com/security/cve/CVE-2021-3490
- http://packetstormsecurity.com/files/164015/Linux-eBPF-ALU32-32-bit-Invalid-Bounds-Tracking-Local-Privilege-Escalation.html
- https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf.git/commit/?id=049c4e13714ecbca567b4d5f6d563f05d431c80e
- https://www.zerodayinitiative.com/advisories/ZDI-21-606/
- https://www.openwall.com/lists/oss-security/2021/05/11/11
- https://ubuntu.com/security/notices/USN-4949-1
- https://ubuntu.com/security/notices/USN-4950-1
- https://github.com/chompie1337/Linux_LPE_eBPF_CVE-2021-3490