SB2021042217 - Ubuntu update for linux

Description

This security bulletin contains information about 2 vulnerabilities.

1) Incorrect authorization (CVE-ID: CVE-2021-3493)

CWE-ID: CWE-863 - Incorrect Authorization

CVSSv4: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:A/U:Clear

The vulnerability allows a local user to execute arbitrary code.

The vulnerability exists due to incorrect authorization error within the validheader() and cap_convert_nscap() functions in security/commoncap.c, within the vfs_setxattr() and setxattr() functions in fs/xattr.c. A local user can execute arbitrary code.

2) Command Injection (CVE-ID: CVE-2021-29154)

CWE-ID: CWE-77 - Command injection

CVSSv4: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear

The vulnerability allows a local user to escalate privileges on the system.

The vulnerability exists due to incorrect computation of branch displacements within the BPF JIT compilers in the Linux kernel in arch/x86/net/bpf_jit_comp.c and arch/x86/net/bpf_jit_comp32.c. A local user can inject and execute arbitrary commands with elevated privileges.

Remediation

Install update from vendor's website.

References

• https://ubuntu.com/security/notices/USN-4916-2