PT-2021-8240 · Linux+3 · Linux Kernel+3

Ryota Shiga · Published 2021-12-14 · Updated 2024-12-02 · CVE-2021-47607

Positive Technologies (AI Summary)

CVSS v3.1

5.5

Medium

Base vector

AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N

Name of the Vulnerable Software and Affected Versions Linux kernel (affected versions not specified)

Description The issue is related to a kernel address leakage in the atomic cmpxchg's r0 aux reg of the BPF component. The implementation of BPF CMPXCHG has parameters including old-val and new-val, where BPF R0 is used as an auxiliary register for input and output. The verifier misses rejecting unprivileged programs where R0 contains a pointer as old value, allowing for kernel address leakage through brute-forcing, which can take approximately 16 seconds.

Recommendations At the moment, there is no information about a newer version that contains a fix for this vulnerability.

Memory Leak

Weakness Enumeration

CWE-401

Related Identifiers

BDU:2024-11584

CVE-2021-47607

OPENSUSE-SU-2024_2372-1

OPENSUSE-SU-2024_2394-1

SUSE-SU-2024:2372-1

SUSE-SU-2024:2394-1

SUSE-SU-2024:2902-1

SUSE-SU-2024:2929-1

SUSE-SU-2024:2939-1

Affected Products

Astra Linux

Linux Kernel

Red Os

Suse

References · 1204

• https://git.kernel.org/stable/c/f87a6c160ecc8c7b417d25f508d3f076fe346136 · Patch
• http://repo.red-soft.ru/redos/7.3c/x86_64/updates · Vendor Advisory
• https://ubuntu.com/security/CVE-2021-47607 · Vendor Advisory
• https://osv.dev/vulnerability/DEBIAN-CVE-2021-47607 · Vendor Advisory
• https://osv.dev/vulnerability/SUSE-SU-2024:2929-1 · Vendor Advisory
• https://osv.dev/vulnerability/SUSE-SU-2024:2902-1 · Vendor Advisory
• https://osv.dev/vulnerability/SUSE-SU-2024:2939-1 · Vendor Advisory
• https://security-tracker.debian.org/tracker/CVE-2021-47607 · Vendor Advisory
• https://cve.org/CVERecord?id=CVE-2021-47607 · Security Note
• https://osv.dev/vulnerability/SUSE-SU-2024:2394-1 · Vendor Advisory
• https://git.kernel.org/stable/c/a82fe085f344ef20b452cd5f481010ff96b5c4cd · Patch
• https://bdu.fstec.ru/vul/2024-11584 · Security Note
• https://osv.dev/vulnerability/UBUNTU-CVE-2021-47607 · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2021-47607 · Security Note
• https://osv.dev/vulnerability/SUSE-SU-2024:2372-1 · Vendor Advisory