CVE-2025-21998Time-of-check Time-of-use (TOCTOU) Race Condition in Linux

Severity
4.7MEDIUMNVD
OSV5.9
EPSS
0.0%
top 88.81%
CISA KEV
Not in KEV
Exploit
No known exploits
Timeline
PublishedApr 3
Latest updateJul 8

Description

In the Linux kernel, the following vulnerability has been resolved: firmware: qcom: uefisecapp: fix efivars registration race Since the conversion to using the TZ allocator, the efivars service is registered before the memory pool has been allocated, something which can lead to a NULL-pointer dereference in case of a racing EFI variable access. Make sure that all resources have been set up before registering the efivars.

CVSS vector

CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:HExploitability: 1.0 | Impact: 3.6

Affected Packages4 packages

NVDlinux/linux_kernel6.116.12.21+2
Debianlinux/linux_kernel< 6.12.21-1+1
CVEListV5linux/linux6612103ec35af6058bb85ab24dae28e119b3c055c4e37b381a7a243c298a4858fc0a5a74e737c79a+3
debiandebian/linux< linux 6.12.21-1 (forky)

Patches

🔴Vulnerability Details

6
OSV
linux-azure, linux-azure-6.11 vulnerabilities2025-07-08
OSV
linux-lowlatency, linux-lowlatency-hwe-6.11 vulnerabilities2025-07-04
OSV
linux-oem-6.11 vulnerabilities2025-06-30
OSV
linux, linux-aws, linux-gcp, linux-gcp-6.11, linux-hwe-6.11, linux-oracle, linux-raspi, linux-realtime vulnerabilities2025-06-30
GHSA
GHSA-6hcp-x8fr-rwcv: In the Linux kernel, the following vulnerability has been resolved: firmware: qcom: uefisecapp: fix efivars registration race Since the conversion t2025-04-03

📋Vendor Advisories

6
Ubuntu
Linux kernel (Azure) vulnerabilities2025-07-08
Ubuntu
Linux kernel (Low Latency) vulnerabilities2025-07-04
Ubuntu
Linux kernel vulnerabilities2025-06-30
Ubuntu
Linux kernel (OEM) vulnerabilities2025-06-30
Red Hat
kernel: firmware: qcom: uefisecapp: fix efivars registration race2025-04-03
CVE-2025-21998 — Linux vulnerability | cvebase