What’s Vulnerable › Vulnerabilities

CVE-2021-35039

• Severity: high (CVSS 7.8 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.3% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2021-07-07 · updated 2026-06-17
• Weakness: CWE-347

Description

kernel/module.c in the Linux kernel before 5.12.14 mishandles Signature Verification, aka CID-0c18f29aae7c. Without CONFIG_MODULE_SIG, verification that a kernel module is signed, for loading via init_module, does not occur for a module.sig_enforce=1 command-line argument.

Affected products

• Debian Linux: 9.0
• Linux kernel: from 4.15 before 4.19.196; from 4.20 before 5.4.129; from 5.5 before 5.10.47; from 5.11 before 5.12.14 — fixed in 4.19.196, 5.10.47, 5.12.14, 5.4.129

How to fix

Upgrade to a fixed version: Linux kernel 4.19.196, 5.10.47, 5.12.14, 5.4.129. Check the vendor advisory for mitigations.

References

• http://www.openwall.com/lists/oss-security/2021/07/06/3
• https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.12.14
• https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=0c18f29aae7ce3dadd26d8ee3505d07cc982df75
• https://github.com/torvalds/linux/commit/0c18f29aae7ce3dadd26d8ee3505d07cc982df75
• https://lists.debian.org/debian-lts-announce/2021/10/msg00010.html
• https://security.netapp.com/advisory/ntap-20210813-0004/
• https://www.openwall.com/lists/oss-security/2021/07/06/3
• http://www.openwall.com/lists/oss-security/2021/07/06/3
• https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.12.14
• https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=0c18f29aae7ce3dadd26d8ee3505d07cc982df75
• https://github.com/torvalds/linux/commit/0c18f29aae7ce3dadd26d8ee3505d07cc982df75
• https://lists.debian.org/debian-lts-announce/2021/10/msg00010.html

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