Cyber Resilience

CVE-2023-20052

XXE in Clamav ≤ 0.103.7

XXE
Published
01 March 2023
Modified
21 November 2024
Patch / advisory
View advisory
CVSS Score v3.1 5.3
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
EPSS Score 0.070 94th percentile
Risk Priority 53 floored blend · peak EPSS

Summary

CVE-2023-20052 is a medium-severity Improper Restriction of XML External Entity Reference (CWE-611) vulnerability in Clamav Clamav. Its CVSS base score is 5.3 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique Endpoint Denial of Service (T1499); ranked in the top 6% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.

Deeper analysis AI-assisted summary

Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.

CVE-2023-20052 is an XML external entity injection vulnerability in the DMG file parser of the ClamAV scanning library, affecting versions 1.0.0 and earlier, 0.105.1 and earlier, and 0.103.7 and earlier. The flaw stems from enabling XML entity substitution, which can be triggered during file scanning and is tracked under CWE-611 and CWE-776.

An unauthenticated remote attacker can exploit the issue by submitting a crafted DMG file for scanning on an affected device. Successful exploitation allows the attacker to leak bytes from any file readable by the ClamAV scanning process, resulting in limited information disclosure with a CVSS 3.1 score of 5.3.

The referenced Cisco Security Advisory at sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-clamav-xxe-TcSZduhN details the vulnerability and associated remediation steps for affected ClamAV deployments.

EPSS for this CVE rose from a low baseline to a peak of 0.1026 on 2025-12-18 before receding to the current value of 0.0355, indicating that exploitation interest emerged after disclosure.

OWASP Top 10 for Web (2025)

A02:2025 Security Misconfiguration

EU & UK References

Vulnerability Data

On Feb 15, 2023, the following vulnerability in the ClamAV scanning library was disclosed: A vulnerability in the DMG file parser of ClamAV versions 1.0.0 and earlier, 0.105.1 and earlier, and 0.103.7 and earlier could allow an unauthenticated, remote attacker…

more

to access sensitive information on an affected device. This vulnerability is due to enabling XML entity substitution that may result in XML external entity injection. An attacker could exploit this vulnerability by submitting a crafted DMG file to be scanned by ClamAV on an affected device. A successful exploit could allow the attacker to leak bytes from any file that may be read by the ClamAV scanning process.

CWE(s)
CWE-611CWE-776

Related Threats

MITRE ATT&CK Enterprise Techniques

T1499 Endpoint Denial of Service Impact
Adversaries may perform Endpoint Denial of Service (DoS) attacks to degrade or block the availability of services to users.
attack.mitre.org →
T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
attack.mitre.org →
T1499.003 Application Exhaustion Flood Impact
Adversaries may target resource intensive features of applications to cause a denial of service (DoS), denying availability to those applications.
attack.mitre.org →
T1005 Data from Local System Collection
Adversaries may search local system sources, such as file systems, configuration files, local databases, virtual machine files, or process memory, to find files of interest and sensitive data prior to Exfiltration.
attack.mitre.org →
T1213 Data from Information Repositories Collection
Adversaries may leverage information repositories to mine valuable information.
attack.mitre.org →
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2023-20032Same product: Cisco Secure Endpoint
CVE-2025-20128Same product: Cisco Secure Endpoint
CVE-2025-20234Same product: Cisco Secure Endpoint
CVE-2026-20216Same product: Cisco Secure Endpoint
CVE-2026-20213Same product: Cisco Secure Endpoint
CVE-2026-20217Same product: Cisco Secure Endpoint
CVE-2026-20215Same product: Cisco Secure Endpoint
CVE-2026-20244Same product: Cisco Secure Endpoint
CVE-2026-20214Same product: Cisco Secure Endpoint
CVE-2026-20243Same product: Cisco Secure Endpoint

Affected Assets

cisco
secure endpoint
≤ 1.20.2 · ≤ 1.21.1 · ≤ 7.5.9
cisco
secure endpoint private cloud
≤ 3.6.0
clamav
clamav
1.0.0 · ≤ 0.103.7 · 0.104.0 — 0.105.1
stormshield
stormshield network security
3.0.0 — 3.7.35 · 3.8.0 — 3.11.23 · 4.3.0 — 4.3.17

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

—

Detect
Catch it (NIST detect / respond)

—

Harden
Shrink the surface (DISA STIG)

—

Validate
Prove the fix (OWASP ASVS)
  • V1.5.1
  • V15.3.2

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.

CA-8 Penetration Testing
addresses: CWE-611

Penetration testing includes XML external entity payloads, detecting XXE vulnerabilities and enabling their mitigation.

SI-4 System Monitoring
addresses: CWE-611

Identifies XML external entity processing via monitoring of unusual file/network access or resource usage.

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 full match
prevents

Secure SDLC practices directly prevent introduction of improper recursive entity handling in XML code.

PR.PS-01 mostly match
prevents

Hardened XML parser configurations directly disable external entity resolution.

ID.RA-01 partial match
prevents

Vulnerability scanning can discover XXE flaws but does not prevent their introduction in code.

PR.PS-02 partial match
prevents

Patching eliminates XXE-vulnerable parser versions but is only one aspect of software maintenance.

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.

A.8.29 Security testing in development and acceptance mostly match
finds

Security testing in development catches XXE via static analysis and dynamic XML fuzzing.

A.8.8 Management of technical vulnerabilities mostly match
finds

Vulnerability management identifies and patches XML libraries with unsafe default entity settings.

A.8.25 Secure development life cycle partial match
prevents

Secure development life cycle mandates input validation and entity handling that directly prevents XXE.

A.8.26 Application security requirements partial match
prevents

Application security requirements explicitly call for disabling external entity processing in XML parsers.

A.8.27 Secure system architecture and engineering principles partial match
prevents

Secure architecture principles include safe parser configuration that mitigates external entity risks.

A.8.28 Secure coding partial match
prevents

Secure coding standards require disabling DTDs and external entities in XML processing.

References