Threats / RARLAB / CVE-2023-38831
CVE-2023-38831
· EUVD no mirror located
· GCVE no mirror located
Verified 2026-06-22
RARLAB WinRAR vulnerability
RARLAB WinRAR contains a code execution vulnerability triggered when users view files in ZIP archives. The flaw is actively exploited in ransomware campaigns.
Verdict
Today item, not a backlog item.
An attacker can achieve arbitrary code execution by crafting a malicious ZIP archive that executes code when a victim opens an apparently benign file. Active exploitation in ransomware operations poses severe risk to organizations.
01
Is it exploitable?
— the evidence, ranked above the scoreExploit available
Public proof-of-concept exploit code is cataloged for this vulnerability.We link the existence of the exploit; we do not host or redistribute payloads.
Reported exploitation
105 independent public reports of in-the-wild exploitation are cataloged.Distinct reporting sources (vendor, incident response, government); open them for the underlying claims.
Exploited in the wild
Listed in the CISA Known Exploited Vulnerabilities catalog (added 2023-08-24), flagged for known ransomware use.
Probability (EPSS)
EPSS 0.97798 — modeled likelihood of exploitation activity.EPSS is a daily-changing model output — open the source for today's value.
Severity / affected
Affected: RARLAB, WinRAR. Confirm exact fixed builds in the vendor advisory.
Weakness (CWE)
Mapped to CWE-351 CWE-351.CWE assignment from the public NVD record; the weakness class drives how the flaw is exploited.
WeaknessCWE-351 · CWE-351
02
Who’s exploiting it?
— attribution turns risk into urgencyAttribution not established
No confirmed (advisory-backed) threat-actor attribution is established for this record. Absence of a named actor is not absence of compromise — see Coverage & confidence.
03
Why it matters
— the attack path, told twice: adversary, then board1
Front door — unauthenticated access narrative 1
Attacker
I craft a ZIP archive containing a benign-looking file paired with malicious payload that triggers on file preview.
Business
Users cannot safely preview archive contents, forcing choice between security risk and operational friction.
2
Keys to the kingdom — privilege/identity takeover narrative 2
Attacker
I distribute the archive via email or file-sharing, relying on user curiosity to open the deceptive file.
Business
Email and endpoint security controls fail to prevent execution, allowing initial compromise of trusted user systems.
3
Lateral reach — past segmentation narrative 3
Attacker
I gain code execution with user privileges and deploy ransomware or lateral movement tools across the network.
Business
Ransomware operators encrypt critical data and demand payment, disrupting operations and threatening data integrity.
04
What to do
— defensible action- Remediate per the vendor advisory — confirm the fixed build for your version and verify exposure.1
Say it to the boardA vulnerability with this evidence profile is a defensible budget line, not a backlog ticket — fund the change against the proof above.
05