Cyber Resilience

CVE-2018-20250

Path Traversal in Rarlab Winrar ≤ 5.61

CISA KEVActive ExploitationEUVD ExploitedPublic PoCRansomware-linkedPath Traversal
Published
05 February 2019
Modified
13 August 2026
KEV Added
15 February 2022
CVSS Score v3.1 7.8
Click a component to see what it means
Raw vectorCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
EPSS Score 0.96 99.9th percentile
Risk Priority 83 floored blend · peak EPSS

Summary

CVE-2018-20250 is a high-severity Absolute Path Traversal (CWE-36) vulnerability in Rarlab Winrar. Its CVSS base score is 7.8 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked in the top 0.1% of CVEs by exploit likelihood; CISA has added it to the Known Exploited Vulnerabilities catalog; a public proof-of-concept is referenced.

Deeper analysis AI-assisted summary

Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.

In WinRAR versions prior to and including 5.61, a path traversal vulnerability exists in the handling of the ACE archive format within UNACEV2.dll. By manipulating the filename field with specific patterns, an attacker can cause the extraction routine to ignore the user-specified destination folder and treat the supplied path as absolute, corresponding to CWE-36 and CWE-22.

The flaw can be exploited by an attacker who supplies a crafted ACE archive to a local user. With low attack complexity and no privileges required, successful exploitation allows arbitrary file writes outside the intended extraction directory, resulting in high impact to confidentiality, integrity, and availability as reflected in the CVSS 7.8 score.

Public references document working proof-of-concept code, a Metasploit module, and detailed technical analysis demonstrating remote code execution via malicious archives, confirming the issue has been weaponized in public tooling.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

In WinRAR versions prior to and including 5.61, There is path traversal vulnerability when crafting the filename field of the ACE format (in UNACEV2.dll). When the filename field is manipulated with specific patterns, the destination (extraction) folder is ignored, thus…

more

treating the filename as an absolute path.

CWE(s)
KEV Date Added
15 February 2022

Related Threats

MITRE ATT&CK Enterprise Techniques

T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2025-6218Same product: Rarlab Winrarboth on KEV
CVE-2024-1708Shared CWE-22both on KEV
CVE-2021-42013Shared CWE-22both on KEV
CVE-2019-7194Shared CWE-22both on KEV
CVE-2024-41713Shared CWE-22both on KEV
CVE-2021-20123Shared CWE-22both on KEV
CVE-2019-16278Shared CWE-22both on KEV
CVE-2019-5418Shared CWE-22both on KEV
CVE-2017-12637Shared CWE-22both on KEV
CVE-2016-3976Shared CWE-22both on KEV

Affected Assets

rarlab
winrar
≤ 5.61

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)
  • V5.3.2

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.

addresses: CWE-22

Validates pathnames and filenames to prevent traversal outside intended directories.

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 input validation and path sanitization that prevent absolute path traversal.

PR.PS-02 partial match
prevents

Patching/maintenance can remediate known path-traversal flaws in deployed software (partial prevention of exploitability) but does nothing to stop the coding defect from being introduced in the first place.

PR.AA-05 none match
prevents

PR.AA-05 defines and reviews access policies but does not address code-level pathname neutralization, so neither direction prevents CWE-22.

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.

finds

Security testing in development can detect absolute path traversal via static analysis and fuzzing.

prevents

Secure development lifecycle includes input validation and path-handling requirements that reduce absolute path traversal risk.

prevents

Application security requirements typically mandate controls against path traversal in file-access functions.

prevents

Secure architecture principles call for canonicalization and sandboxing that limit absolute path traversal.

prevents

Secure coding standards directly require neutralization of absolute path sequences in pathname construction.

mitigates

Information access restriction limits which files can be reached but does not address the path-construction flaw itself.

References