{"id":55083,"date":"2025-06-25T09:49:20","date_gmt":"2025-06-25T09:49:20","guid":{"rendered":""},"modified":"2025-09-03T02:35:40","modified_gmt":"2025-09-03T08:35:40","slug":"cve-2025-20260-buffer-overflow-vulnerability-in-clamav-s-pdf-scanning-process","status":"publish","type":"post","link":"https:\/\/www.ameeba.com\/blog\/cve-2025-20260-buffer-overflow-vulnerability-in-clamav-s-pdf-scanning-process\/","title":{"rendered":"CVE-2025-20260: Buffer Overflow Vulnerability in ClamAV’s PDF Scanning Process<\/strong>"},"content":{"rendered":"

Overview<\/strong><\/p>\n

In the ever-evolving landscape of cybersecurity, vulnerabilities are often discovered that can potentially compromise system security or result in data leakage. One such vulnerability, identified as CVE-2025-20260, has been detected in the PDF scanning processes of ClamAV, a popular open-source antivirus engine. This vulnerability affects any system or device that utilizes the ClamAV engine for scanning PDF<\/a> files. The matter is of utmost importance as it might allow an unauthenticated, remote attacker to cause a buffer overflow<\/a> condition, leading to a denial of service (DoS) or potentially executing arbitrary code on the affected device.<\/p>\n

Vulnerability Summary<\/strong><\/p>\n

CVE ID: CVE-2025-20260
\nSeverity: Critical (CVSS: 9.8)
\nAttack Vector: Network
\nPrivileges Required: None
\nUser Interaction: None
\nImpact: Buffer overflow<\/a> potentially leading to a denial of service condition or execution of arbitrary code on the affected system.<\/p>\n

Affected Products<\/strong><\/p>\n

Product | Affected Versions<\/p>\n

ClamAV | All versions up to the latest release<\/p>\n

How the Exploit Works<\/strong><\/p>\n

The vulnerability arises due to incorrect memory buffer<\/a> allocation when ClamAV processes PDF files. An attacker can exploit this vulnerability by crafting a malicious PDF file<\/a> and submitting it to be scanned by ClamAV on the affected device. If successful, this could trigger a buffer overflow<\/a> condition, likely resulting in the termination of the ClamAV scanning process and a DoS condition on the affected software. Although not yet proven, it is also possible that an attacker could leverage this buffer overflow<\/a> to execute arbitrary code with the privileges of the ClamAV process.<\/p>\n

Conceptual Example Code<\/strong><\/p>\n

Here’s a conceptual example of how this vulnerability might be exploited. This pseudocode represents a maliciously crafted PDF file:<\/p>\n

# Pseudocode representing a malicious PDF\nclass MaliciousPDF:\ndef __init__(self):\nself.payload = \"A\"*5000  # Overflows the buffer\nmalicious_pdf = MaliciousPDF()\nClamAV.scan(malicious_pdf)  # Triggers buffer overflow<\/code><\/pre>\n
In the above example, the payload is an extremely large string designed to overflow the buffer<\/a> when scanned by ClamAV.<\/p>\n
Recommendations<\/strong><\/p>\n
The recommended mitigation for this vulnerability is to apply the patch provided<\/a> by the vendor as soon as it is available. As a temporary countermesure, you can use a Web Application Firewall (WAF) or Intrusion Detection System (IDS) to identify and block potential attacks<\/a>. Users are also advised to avoid scanning unsolicited PDF files and to only scan files from trusted sources.
\nStay tuned for more updates on this and other cybersecurity vulnerabilities<\/a>. Protecting your systems and data<\/a> is our top priority.<\/p>\n","protected":false},"excerpt":{"rendered":"
Overview In the ever-evolving landscape of cybersecurity, vulnerabilities are often discovered that can potentially compromise system security or result in data leakage. One such vulnerability, identified as CVE-2025-20260, has been detected in the PDF scanning processes of ClamAV, a popular open-source antivirus engine. This vulnerability affects any system or device that utilizes the ClamAV engine […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"om_disable_all_campaigns":false,"_monsterinsights_skip_tracking":false,"footnotes":""},"categories":[1],"tags":[],"vendor":[],"product":[],"attack_vector":[86,87],"asset_type":[],"severity":[],"exploit_status":[],"class_list":["post-55083","post","type-post","status-publish","format-standard","hentry","category-uncategorized","attack_vector-buffer-overflow","attack_vector-dos"],"aioseo_notices":[],"aioseo_head":"\n\t\t\n\t\n\t\n\t\n\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t