CVE-2021-29648

An issue was discovered in the Linux kernel before 5.11.11. The BPF subsystem does not properly consider that resolved_ids and resolved_sizes are intentionally uninitialized in the vmlinux BPF Type Format (BTF), which can cause a system crash upon an unexpected access attempt (in map_create in kernel/bpf/syscall.c or check_btf_info in kernel/bpf/verifier.c), aka CID-350a5c4dd245.

Weakness

The product does not implement sufficient measures to prevent multiple failed authentication attempts within a short time frame, making it more susceptible to brute force attacks.

Affected Software

Potential Mitigations

• Common protection mechanisms include:

• Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.

• Consider using libraries with authentication capabilities such as OpenSSL or the ESAPI Authenticator. [REF-45]

Related Attack Patterns

• https://cwe.mitre.org/data/definitions/16.html
• https://cwe.mitre.org/data/definitions/49.html
• https://cwe.mitre.org/data/definitions/560.html
• https://cwe.mitre.org/data/definitions/565.html
• https://cwe.mitre.org/data/definitions/600.html
• https://cwe.mitre.org/data/definitions/652.html
• https://cwe.mitre.org/data/definitions/653.html

References

• https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.11.11
• https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=350a5c4dd2452ea999cc5e1d4a8dbf12de2f97ef
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/RZGMUP6QEHJJEKPMLKOSPWYMW7PXFC2M/
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/VTADK5ELGTATGW2RK3K5MBJ2WGYCPZCM/
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/WKRNELXLVFDY6Y5XDMWLIH3VKIMQXLLR/