CVE-2020-9308Network attack vector

Archive parser crash via invalid RAR5 header

Published Feb 20, 2020 · Updated Aug 4, 2024

Improper input validation in libarchive before 3.4.2 allows remote attackers to crash archive processing via a crafted RAR5 file. The archive_read_support_format_rar5.c parser accepts a zero or undersized RAR5 base-block header and then dereferences invalid state, producing SIGSEGV during unpacking. Exploitation requires a victim process to open the malformed archive; the documented consequence is a denial of service, with other impact unspecified.

CVSS severity8.8
High
EPSS probability2.25%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper input validation in libarchive before 3.4.2 allows remote attackers to crash archive processing via a crafted RAR5 file. The archive_read_support_format_rar5.c parser accepts a zero or undersized RAR5 base-block header and then dereferences invalid state, producing SIGSEGV during unpacking. Exploitation requires a victim process to open the malformed archive; the documented consequence is a denial of service, with other impact unspecified.

The record

CVE
CVE-2020-9308
Published
Feb 20, 2020
Updated
Aug 4, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-20, CWE-787, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Feb 20, 2020CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

8.8National Vulnerability DatabaseCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-20Improper Input Validation
CWE-787Out-of-bounds Write
T1499.004Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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