Vulnerability report

Exploited in the wild Confirmed confidence In CISA KEV

CVE-2023-38831

WinRAR

RARLAB / WinRAR · affected before 6.23

Watch CVE-2023-38831 Browse KEV feed
Severity
CVSS 7.8 · High
Confidence
Confirmed
Exploit status
Exploited in the wild
EPSS
99.8%
First observed
—
Last observed
—

Decision summary

What security teams need to know first

Direct answers before the deeper technical record.

What it is

CVE-2023-38831 is an unauthenticated vulnerability affecting RARLAB WinRAR. 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...

Is it exploited?

Yes. Previdian tracks this CVE as a known exploited vulnerability. Confidence is confirmed. Listed in CISA KEV. Also confirmed by third-party sources.

Who is affected?

RARLAB / WinRAR affected before 6.23.

What should we do?

Prioritize remediation. Validate affected assets and apply vendor fixes on an accelerated timeline.

Overview

WinRAR

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 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.

rarlab Affected
winrar
Before 6.23
Published
23 Aug 2023
Exploitation Reported
24 Aug 2023
Attack vector
Local
Complexity
Low
Privileges
None
User interaction
Required

Tags

windows malware metasploit ransomware cisa

CVE References

Exploitation evidence

Why Previdian marks this CVE as exploited

Third-party attestation and first-party sensor observation are shown separately so teams can judge the evidence chain.

Exploited in the wild

CISA

Recorded 24 Aug 2023

A trusted third party reported exploitation.

Used in malware

CISA

Recorded 24 Aug 2023

Malware families have been linked to exploitation of this CVE.

Proof of concept available

GitHub

Recorded 24 Aug 2023

Public scanner or PoC coverage increases practical exploitability.

Known exploited vulnerability sources

Per-source evidence links for KEV attestations are available through the Previdian Pro API.

Learn about Pro API access
Source Added
CISA First 2023-08-24 00:00 UTC
CVE 2026-08-05 04:30 UTC

Detection

Operational artifacts and observed signals

Make the evidence actionable in scanner, SOC, and edge-control workflows.

Observed signals

Request targets
User-Agents
Callback hosts
0
0
0

Request targets and User-Agents available in Pro. Callback host details available in Enterprise.

Virtual patch status

No Previdian virtual patch is currently available. Future rules ship for ModSecurity, Cloudflare, and AWS WAF.

Learn about virtual patches →

Scanner Artifacts

Scanner and exploit-framework references linked to this CVE.

Scanner Reference Detected
Metasploit https://github.com/rapid7/metasploit-framework/blob/master/modules/exploits/windows/fileformat/winrar_cve_2023_38831.rb 28 Apr 2025

Risk and context

Severity, weaknesses, and research context

CVSS v3.1

7.8 High

Potential damage if exploited. Separate from whether attackers are using it.

CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

EPSS

99.8%

Estimated chance of exploitation in the next 30 days. Previdian's warning comes from evidence, not this score.

Weaknesses

Insufficient Type Distinction CWE-351

Recent mention · The Hacker News

ThreatsDay: AI Search Poisoning, AI Coding Tool Leaking Repos, One-Click Code Execution and 13 More Stories

Ravie LakshmananSep 24, 2026Hacking News / Cybersecurity News This week, the dangerous stuff keeps arriving dressed as something boring. An update. A login box. A search answer. A coding tool. A link you have clicked a hundred times before. That is the thread running through...

Read full advisory

All Mentions

Recent mention · The Hacker News

ThreatsDay: AI Search Poisoning, AI Coding Tool Leaking Repos, One-Click Code Execution and 13 More Stories

The Hacker News · 24 Sep 2026

Ravie LakshmananSep 24, 2026Hacking News / Cybersecurity News This week, the dangerous stuff keeps arriving dressed as something boring. An update. A login box. A search answer. A coding tool. A link you have clicked a hundred times before. That is the thread running through the pile. Trusted paths get poisoned. Old bugs find new jobs. AI tools leak more than expected. Fake prompts look real enough. And some attacks barely need an exploit at all — just one weak setting or one person doing what the screen tells them. Nothing here looks especially dramatic. That is what makes it useful. The...

Recent mention · Huntress Blog

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Huntress Blog · 22 Sep 2026

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Potential Proof of Concepts

These PoCs are unverified and could contain malware. Use at your own risk.

winrar_cve_2023_38831

metasploit · Created Unknown

Metasploit module for CVE-2023-38831

Timeline

From disclosure to observed exploitation

  1. 04:30 UTC

    KEV confirmed by CVE

    Exploitation attested by an external source

  2. 15:02 UTC

    Metasploit module available

    Exploit module available

  3. 15:02 UTC

    Public PoC available

    Public proof-of-concept code published

  4. 00:00 UTC

    Added to CISA KEV

    Listed in the CISA Known Exploited Vulnerabilities catalog

  5. 00:00 UTC

    First public exploitation report

    Exploit observed in malware

  6. 00:00 UTC

    CVE published

    Vulnerability disclosed publicly

  7. 00:00 UTC

    CVE ID reserved

    Identifier reserved by the CNA

Pro API

Automate this intelligence

Confidence, exploit status, sensor telemetry, PoCs, scanner integrations, mentions, and tags are available programmatically for VM, SOC, and CTI workflows.

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  • Evidence confidence and provenance
  • First-party sensor telemetry
  • PoC and scanner references
  • Affected versions and enrichment
  • Automation-ready JSON delivery

GET /api/v2/pro/kevs/CVE-2023-38831

Sample API response 
{
  "cve_id": "CVE-2023-38831",
  "confidence": "Confirmed",
  "cvss_score": 7.8,
  "cvss_estimated": false,
  "epss_score": 0.99815,
  "exploit_status": {
    "exploited_in_the_wild": true,
    "active_exploitation_observed": false
  },
  "sensor_telemetry": { "attempts": 0, "sensors": 0 }
}