CVE-2024-20505VulnerabilityPublished 4 Sep 2024Updated 3 Nov 2025

CVE-2024-20505: Cisco ClamAV · Vulnerability

Affects Cisco ClamAVSource CVE Database V5

Not known to be exploited · CVSS 4.0 Medium · fixed in 1.3.0 : update Cisco ClamAV when convenient.

Data as of 26 Oct 2026, 06:26 UTC

CVSS 3.1 base score

4.0Medium

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 0.5% chance of exploitation in 30 days – higher than 46% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 1.3.0, 0.106.0, 0.105.0

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

Attack Vector: Local
Attack Complexity: Low
Privileges Required: None
User Interaction: None
Scope: Unchanged
Confidentiality: None
Integrity: None
Availability: Low

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Local: The vulnerable component is not bound to the network stack and the attacker’s path is via read/write/execute capabilities. Either: the attacker exploits the vulnerability by accessing the target system locally (e.g., keyboard, console), or remotely (e.g., SSH); or the attacker relies on User Interaction by another person to perform actions required to exploit the vulnerability (e.g., tricking a legitimate user into opening a malicious document).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: None: There is no loss of confidentiality within the impacted component.
Integrity: None: There is no loss of integrity within the impacted component.
Availability: Low: Performance is reduced or there are interruptions in resource availability. Even if repeated exploitation of the vulnerability is possible, the attacker does not have the ability to completely deny service to legitimate users. The resources in the impacted component are either partially available all of the time, or fully available only some of the time, but overall there is no direct, serious consequence to the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 4 Sep 2024
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 2026-10-26.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade Cisco ClamAV to 1.3.0, 0.106.0 or 0.105.0.

Affected software

Product	Affected	Fixed in
Cisco ClamAV	Affected =1.4.0 =1.3.2 =1.0.6 =1.0.5 =1.0.4 =1.0.3 =1.0.2 =1.0.1 =1.0.0 >=1.2.0 <1.3.0 >=0.105.0 <0.106.0 >=0.104.0 <0.105.0 =0.103.11 =0.103.10 =0.103.9 =0.103.8 =0.103.7 =0.103.6 =0.103.5 =0.103.4 =0.103.3 =0.103.2 =0.103.1 =0.103.0	Fixed in 1.3.0 0.106.0 0.105.0

AI-suggested

European organizations should implement the following mitigations: 1) Restrict or monitor PDF files submitted for scanning, especially from untrusted or external sources, to reduce exposure to crafted malicious PDFs. 2) Deploy ClamAV in isolated or sandboxed environments where possible to limit impact of crashes. 3) Implement redundancy in malware scanning infrastructure to maintain availability if one scanner instance is disrupted. 4) Monitor ClamAV logs and system stability for signs of crashes or abnormal termination. 5) Prepare for timely patching by tracking Cisco advisories and ClamAV updates, as no patches are currently available. 6) Consider alternative or additional antivirus engines for PDF scanning until a fix is released. 7) Educate security teams about this vulnerability to enhance incident detection and response readiness. 8) Limit network access to scanning services to trusted users or systems to reduce attack surface.

Description

A vulnerability in the PDF parsing module of Clam AntiVirus (ClamAV) versions 1.4.0, 1.3.2 and prior versions, all 1.2.x versions, 1.0.6 and prior versions, all 0.105.x versions, all 0.104.x versions, and 0.103.11 and all prior versions could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. The vulnerability is due to an out of bounds read. An attacker could exploit this vulnerability by submitting a crafted PDF file to be scanned by ClamAV on an affected device. An exploit could allow the attacker to terminate the scanning process.

Impact

For European organizations, the primary impact is availability degradation of antivirus scanning services, potentially allowing malicious files to bypass detection during downtime. This can affect mail gateways, file servers, and endpoint protection systems that integrate ClamAV for malware scanning. Disruption in scanning may delay threat detection and response, increasing exposure to malware. Organizations in sectors with high reliance on PDF document exchange, such as finance, legal, and government, may face operational interruptions. Additionally, critical infrastructure and managed security service providers using ClamAV appliances could experience service outages. While the vulnerability does not lead to data breaches or system compromise directly, the denial of service could be leveraged as part of multi-stage attacks to weaken defenses. The lack of known exploits reduces immediate risk, but the widespread use of ClamAV in Europe means the vulnerability warrants attention.

CWE-125Out-of-bounds Read (opens in a new tab)
Base weaknessCWE Top 25 (2025): #8
The product reads data past the end, or before the beginning, of the intended buffer.
Implementation · Input Validation
Assume all input is malicious. Use an "accept known good" input validation strategy, i.e., use a list of acceptable inputs that strictly conform to specifications. Reject any input that does not strictly conform to specifications, or transform it into something that does.
Architecture and Design · Language Selection
Use a language that provides appropriate memory abstractions.
OWASP Cheat Sheets
XML Security (opens in a new tab)
Mass Assignment (opens in a new tab)
OWASP ASVS 4.0.3
V13.3.1 (opens in a new tab)
V5.1.4 (opens in a new tab)
V5.1.3 (opens in a new tab)
Attack patterns
Overread Buffers (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 3 Nov 2025, 23:44 UTC

WeaknessesCWE-125

Technical details

References

Community reviews

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