Cyber Resilience

CVE-2023-6857

Race Condition in Debian Linux 10.0 … 12.0

Race Condition
Published
19 December 2023
Modified
21 November 2024
Patch / advisory
View advisory
CVSS Score v3.1 5.3
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:H/A:N
EPSS Score 0.0066 49th percentile
Risk Priority 43 floored blend · peak EPSS

Summary

CVE-2023-6857 is a medium-severity Race Condition (CWE-362) vulnerability in Debian Debian Linux. Its CVSS base score is 5.3 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Privilege Escalation (T1068); ranked at the 49th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

OWASP Top 10 for Web (2025)

A06:2025 Insecure Design

EU & UK References

Vulnerability Data

When resolving a symlink, a race may occur where the buffer passed to `readlink` may actually be smaller than necessary. *This bug only affects Firefox on Unix-based operating systems (Android, Linux, MacOS). Windows is unaffected.* This vulnerability affects Firefox ESR…

more

< 115.6, Thunderbird < 115.6, and Firefox < 121.

CWE(s)
CWE-362

Related Threats

MITRE ATT&CK Enterprise Techniques

T1068 Exploitation for Privilege Escalation Privilege Escalation
Adversaries may exploit software vulnerabilities in an attempt to elevate privileges.
attack.mitre.org →
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2026-7960Same product: Apple Macos
CVE-2025-13721Same product: Apple Macos
CVE-2026-5902Same product: Apple Macos
CVE-2026-8520Same product: Apple Macos
CVE-2026-5890Same product: Apple Macos
CVE-2026-7954Same product: Apple Macos
CVE-2025-8880Same product: Apple Macos
CVE-2026-10006Same product: Apple Macos
CVE-2026-13882Same product: Apple Macos
CVE-2026-2319Same product: Apple Macos

Affected Assets

mozilla
firefox
≤ 121.0
mozilla
firefox esr
≤ 115.6
mozilla
thunderbird
≤ 115.6
debian
debian linux
10.0, 11.0, 12.0

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

—

Detect
Catch it (NIST detect / respond)

—

Harden
Shrink the surface (DISA STIG)

—

Validate
Prove the fix (OWASP ASVS)
  • V10.4.2
  • V10.4.5
  • V15.1.3
  • V15.4.1

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

AU-8 Time Stamps
addresses: CWE-362

Accurate timestamps from internal clocks enable detection of race conditions by providing reliable event ordering in audit logs.

PL-6 Security-related Activity Planning
addresses: CWE-362

Coordination of concurrent security activities reduces the probability that shared resources will be accessed simultaneously without proper synchronization.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-06 mostly match
prevents

Secure SDLC practices directly require proper synchronization primitives and concurrency testing that prevent race conditions.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

A.8.29 Security testing in development and acceptance mostly match
finds

Security testing can detect race conditions, but does not prevent them at design or coding time.

A.8.25 Secure development life cycle partial match
prevents

Secure SDLC mandates concurrency controls and synchronization primitives that directly prevent race conditions.

A.8.26 Application security requirements partial match
prevents

Application security requirements can specify thread-safety and locking rules, but do not prescribe implementation details.

A.8.27 Secure system architecture and engineering principles partial match
prevents

Secure architecture principles require proper synchronization and resource isolation, addressing the root cause of CWE-362.

A.8.28 Secure coding partial match
prevents

Secure coding standards explicitly forbid unsafe concurrent access patterns and mandate atomic operations or locks.

A.8.32 Change management none match
none

Change management reduces introduction of concurrency bugs during updates, yet does not address the weakness itself.

References