CVE-2021-34556

MEDIUM

Linux Kernel < 5.13.7 - Information Disclosure via BPF Speculative Store Bypass

Title source: llm

Description

In the Linux kernel through 5.13.7, an unprivileged BPF program can obtain sensitive information from kernel memory via a Speculative Store Bypass side-channel attack because the protection mechanism neglects the possibility of uninitialized memory locations on the BPF stack.

References (6)

Core 6

Core References

Patch, Vendor Advisory x_refsource_misc

https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/patch/?id=f5e81d1117501546b7be050c5fbafa6efd2c722c

Patch, Vendor Advisory x_refsource_misc

https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/patch/?id=2039f26f3aca5b0e419b98f65dd36481337b86ee

Mailing List x_refsource_misc

http://www.openwall.com/lists/oss-security/2021/08/01/3

Mailing List, Third Party Advisory vendor-advisory x_refsource_fedora

https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/6JKK6XNRZX5BT5QVYOKGVJ2BHFZAP5EX/

Mailing List, Third Party Advisory vendor-advisory x_refsource_fedora

https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/565ZS55ZFEN62WVRRORT7R63RXW5F4T4/

Mailing List, Third Party Advisory mailing-list x_refsource_mlist

https://lists.debian.org/debian-lts-announce/2021/10/msg00010.html

Scores

CVSS v3 5.5

EPSS 0.0004

EPSS Percentile 12.9%

Attack Vector LOCAL

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N

Details

CWE

CWE-203

Status published

Products (4)

debian/debian_linux 9.0

fedoraproject/fedora 33

fedoraproject/fedora 34

linux/linux_kernel < 5.13.7

Published Aug 02, 2021

Tracked Since Feb 18, 2026