CVE-2021-34556 — Observable Discrepancy in Linux

CWE-203 — Observable DiscrepancyCWE-200 — Sensitive Information Exposure20 documents7 sources
Severity
5.5MEDIUMNVD
OSV7.8OSV6.5OSV4.7
EPSS
0.0%
top 87.60%
CISA KEV
Not in KEV
Exploit
No known exploits
Affected products
6
Linux KernelDebian LinuxDebian Linux+3 more
Timeline
PublishedAug 2
Latest updateJun 1

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.

CVSS vector

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:NExploitability: 1.8 | Impact: 3.6

Affected Packages6 packages

▶Debianlinux/linux_kernel< 5.10.46-4+3
▶Ubuntulinux/linux_kernel< 5.4.0-90.101
▶NVDlinux/linux_kernel5.13.7

Also affects: Debian Linux 9.0, Fedora 33, 34

Patches

Patch: git.kernel.org ↗Patch: git.kernel.org ↗Patch: git.kernel.org ↗

🔴Vulnerability Details

10
OSV
CVE-2021-34556: In check_stack_write_fixed_off and related functions of verifier↗2022-06-01
▶
GHSA
GHSA-r297-r893-jqqx: In the Linux kernel through 5↗2022-05-24
▶
OSV
linux-bluefield, linux-gke-5.4, linux-oracle, linux-oracle-5.4, linux-raspi, linux-raspi-5.4 vulnerabilities↗2021-11-11
▶
OSV
linux, linux-aws, linux-aws-5.4, linux-azure, linux-azure-5.4, linux-gcp, linux-gcp-5.4, linux-gke, linux-gkeop, linux-gkeop-5.4, linux-hwe-5.4, linux-ibm, linux-kvm vulnerabilities↗2021-11-09
▶
OSV
linux-oem-5.10 vulnerabilities↗2021-10-20
▶

📋Vendor Advisories

9
Ubuntu
Linux kernel vulnerabilities↗2021-11-11
▶
Ubuntu
Linux kernel vulnerabilities↗2021-11-09
▶
Ubuntu
Linux kernel (OEM) vulnerabilities↗2021-10-20
▶
Ubuntu
Linux kernel (Azure) regression↗2021-10-18
▶
Ubuntu
Linux kernel vulnerabilities↗2021-09-29
▶
CVE-2021-34556 — Observable Discrepancy in Debian Linux | cvebase