Cyber Resilience

CVE-2023-38831

Rarlab Winrar ≤ 6.23

CISA KEVActive ExploitationEUVD ExploitedPublic PoCRansomware-linked
Published
23 August 2023
Modified
05 August 2026
KEV Added
24 August 2023
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 0.98 99.9th percentile
Risk Priority 83 floored blend · peak EPSS

Summary

CVE-2023-38831 is a high-severity Insufficient Verification of Data Authenticity (CWE-345) vulnerability in Rarlab Winrar. Its CVSS base score is 7.8 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Mark-of-the-Web Bypass (T1553.005); 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.

RARLAB WinRAR versions prior to 6.23 contain a path-handling flaw that permits arbitrary code execution. When a user opens or previews a seemingly benign file such as a .JPG inside a ZIP archive, the application also processes a folder that shares the same name as the file; any executable content placed inside that folder is executed with the privileges of the user. The vulnerability is tracked as CWE-345 and CWE-351 and carries a CVSS 3.1 score of 7.8.

An attacker can deliver a crafted ZIP archive via email, download, or removable media. Once the recipient attempts to view the innocuous file, the hidden folder contents run automatically, granting the attacker remote code execution on the local system without further user interaction beyond opening the archive.

WinRAR 6.23 and subsequent releases correct the folder-name collision logic. Security advisories and vendor guidance therefore recommend immediate upgrade; organizations should also verify that older builds are removed from endpoints and build pipelines.

The issue was exploited in the wild from April through October 2023, including campaigns attributed to government-backed actors that targeted cryptocurrency trading accounts. The current EPSS of 0.9386, near its recorded peak of 0.9395, reflects sustained attacker interest after public disclosure.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

RARLAB WinRAR before 6.23 allows attackers to execute arbitrary code when a user attempts to view a benign file within a ZIP archive. The issue occurs because a ZIP archive may include a benign file (such as an ordinary .JPG…

more

file) and also a folder that has the same name as the benign file, and the contents of the folder (which may include executable content) are processed during an attempt to access only the benign file. This was exploited in the wild in April through October 2023.

CWE(s)
KEV Date Added
24 August 2023

Related Threats

MITRE ATT&CK Enterprise Techniques

T1553.005 Mark-of-the-Web Bypass Defense Impairment
Adversaries may abuse specific file formats to subvert Mark-of-the-Web (MOTW) controls.
T1195 Supply Chain Compromise Initial Access
Adversaries may manipulate products or product delivery mechanisms prior to receipt by a final consumer for the purpose of data or system compromise.
T1195.001 Compromise Software Dependencies and Development Tools Initial Access
Adversaries may manipulate software dependencies and development tools prior to receipt by a final consumer for the purpose of data or system compromise.
T1195.002 Compromise Software Supply Chain Initial Access
Adversaries may manipulate application software prior to receipt by a final consumer for the purpose of data or system compromise.
T1542.002 Component Firmware Stealth
Adversaries may modify component firmware to persist on systems.
T1553 Subvert Trust Controls Defense Impairment
Adversaries may undermine security controls that will either warn users of untrusted activity or prevent execution of untrusted programs.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2018-20250Same product: Rarlab Winrarboth on KEV
CVE-2023-40477Same product: Rarlab Winrar
CVE-2024-30370Same product: Rarlab Winrar
CVE-2025-31334Same product: Rarlab Winrar
CVE-2025-52331Same product: Rarlab Winrar
CVE-2025-6218Same product: Rarlab Winrarboth on KEV
CVE-2022-26871Shared CWE-345both on KEV
CVE-2025-8088Same product: Rarlab Winrarboth on KEV
CVE-2023-2866Shared CWE-345, CWE-351
CVE-2024-36052Same product: Rarlab Winrar

Affected Assets

rarlab
winrar
≤ 6.23

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

Detect
Catch it (NIST detect / respond)

Harden
Shrink the surface (DISA STIG)
  • 8 hardening rules · 5 OS baselines
Validate
Prove the fix (OWASP ASVS)
  • V3.5.5
  • V1.5.3

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-345

Directly requires independent verification of matching output before adverse decisions, mitigating insufficient authenticity checks on data from external sources.

addresses: CWE-345

Use of approved PKI certificates provides verifiable data authenticity and origin for communications and artifacts.

addresses: CWE-345

Mandates provision of authenticity and integrity artifacts that enable verification of name/address resolution data.

addresses: CWE-345

Requires explicit verification of data authenticity from authoritative sources, preventing acceptance of unauthenticated resolution responses.

addresses: CWE-345

Control requires verification of data authenticity/integrity (e.g., checksums) after aggregation/packing, directly reducing exploitation of insufficient verification before transmission.

addresses: CWE-345

Time synchronization supports reliable freshness verification when checking data authenticity across systems or components.

addresses: CWE-345

Mandates verification of data authenticity for software, firmware, and information.

addresses: CWE-345

Provenance documentation and monitoring directly enables verification of authenticity for components and data throughout their history.

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 prevent type-distinction flaws during development while the control addresses the full lifecycle.

RC.RP-05 mostly match
degrades

CWE-345 directly impairs RC.RP-05's verification of restored-asset integrity/authenticity, largely defeating the outcome while still leaving other restoration-confirmation steps partially viable.

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 can detect missing or weak data authenticity verification.

mitigates

Network controls can enforce authenticated channels, reducing risk of accepting unauthentic data.

mitigates

Secure network services often include authenticity checks for data exchanged over those services.

prevents

Cryptographic mechanisms directly verify data origin and integrity, preventing acceptance of unauthentic data.

prevents

Secure SDLC incorporates authenticity verification requirements throughout development.

prevents

Application security requirements can mandate data authenticity verification mechanisms.

Hardening callouts derived

Configuration rules from DISA STIG baselines that bear on weaknesses of the type cited by this CVE. Each rule is shown with the relationship its mapping actually records, against the CWE it was authored against. Derived via CVE→CWE over `controls_xwalks` (authoritative rows only; rows rated `none` are excluded).

Oracle Linux 8 (2 rules)
  • V-248574 YUM must be configured to prevent the installation of patches, service packs, device drivers, or OL 8 system components that have not been digitally signed using a certificate that is recognized and approved by the organization. prevents CWE-345
  • V-248575 OL 8 must prevent the installation of software, patches, service packs, device drivers, or operating system components of local packages without verification they have been digitally signed using a certificate that is issued by a Certificate Authority (CA) that is recognized and approved by the organization. prevents CWE-345
Oracle Linux 9 (1 rule)
  • V-271525 OL 9 must have GPG signature verification enabled for all software repositories. prevents CWE-345
RHEL 7 (2 rules)
  • V-204447 The Red Hat Enterprise Linux operating system must prevent the installation of software, patches, service packs, device drivers, or operating system components from a repository without verification they have been digitally signed using a certificate that is issued by a Certificate Authority (CA) that is recognized and approved by the organization. prevents CWE-345
  • V-204448 The Red Hat Enterprise Linux operating system must prevent the installation of software, patches, service packs, device drivers, or operating system components of local packages without verification they have been digitally signed using a certificate that is issued by a Certificate Authority (CA) that is recognized and approved by the organization. prevents CWE-345
RHEL 8 (2 rules)
  • V-230264 RHEL 8 must prevent the installation of software, patches, service packs, device drivers, or operating system components from a repository without verification they have been digitally signed using a certificate that is issued by a Certificate Authority (CA) that is recognized and approved by the organization. prevents CWE-345
  • V-230265 RHEL 8 must prevent the installation of software, patches, service packs, device drivers, or operating system components of local packages without verification they have been digitally signed using a certificate that is issued by a Certificate Authority (CA) that is recognized and approved by the organization. prevents CWE-345
RHEL 9 (1 rule)
  • V-257822 RHEL 9 must have GPG signature verification enabled for all software repositories. prevents CWE-345

References