CVE-2021-3444
HighThe bpf verifier in the Linux kernel did not properly handle mod32 destination register truncation when the source register was known to be 0. A local attacker with the ability to load bpf programs could use this gain out-of-bounds reads in kernel memory leading to information disclosure (kernel memory), and possibly out-of-bounds writes that could potentially lead to code execution. This issue was addressed in the upstream kernel in commit 9b00f1b78809 ("bpf: Fix truncation handling for mod32 dst reg wrt zero") and in Linux stable kernels 5.11.2, 5.10.19, and 5.4.101.
CVSS 3.1 score
7.8
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Weakness type
CWE-681CVE-2021-3444 is a Incorrect Conversion Between Numeric Types vulnerability
What is Incorrect Conversion Between Numeric Types?
The product converts from one data type to another but uses a function that can produce incorrect results. Learn more on MITRE CWE
References
The following references provide additional information about CVE-2021-3444 including vendor advisories, patch commits, exploit details, and third-party analysis. Links are sourced from the NIST NVD database.
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Packet Stormhttp://packetstormsecurity.com/files/162117/Kernel-Live-Patch-Security-Notice-LSN-0075-1.htmlThird Party Advisory VDB Entry
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Packet Stormhttp://packetstormsecurity.com/files/164950/Kernel-Live-Patch-Security-Notice-LSN-0082-1.htmlThird Party Advisory VDB Entry
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Mailing List Third Party Advisory
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Mailing List Third Party Advisory
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Third Party Advisory
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Mailing List Third Party Advisory
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PatchKernel patch commithttps://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=9b00f1b78809
Frequently asked questions
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What is CVE-2021-3444?
CVE-2021-3444 is a High severity Linux kernel vulnerability with a CVSS score of 7.8 out of 10 , classified as an Incorrect Conversion Between Numeric Types flaw (CWE-681) . CVE-2021-3444 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
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What is the CVSS score for CVE-2021-3444?
CVE-2021-3444 has a CVSS score of 7.8 out of 10, rated High severity (CVSS 3.1). The vector string is
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H. -
Is there a patch available for CVE-2021-3444?
No patch is currently available for CVE-2021-3444. Monitor the NIST NVD and your Linux distribution's security advisories for updates.
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Is CVE-2021-3444 actively exploited?
No — CVE-2021-3444 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.
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What is Incorrect Conversion Between Numeric Types (CWE-681)?
The product converts from one data type to another but uses a function that can produce incorrect results. View CWE-681 on MITRE CWE →