Overview
In the rapidly evolving realm of cybersecurity, vulnerabilities that allow unauthorized access pose a significant threat to the integrity of systems and data. The recent discovery of CVE-2025-53499, a Missing Authorization vulnerability in Wikimedia Foundation’s Mediawiki – AbuseFilter Extension, emphasizes this ongoing issue. This vulnerability, which affects versions 1.43.X before 1.43.2 of the AbuseFilter Extension, can potentially lead to system compromise and data leakage. Given the wide usage and influence of Mediawiki, this issue has widespread implications and deserves immediate attention.
Vulnerability Summary
CVE ID: CVE-2025-53499
Severity: Critical (9.1 CVSS Score)
Attack Vector: Network
Privileges Required: None
User Interaction: Required
Impact: Unauthorized Access, Potential System Compromise and Data Leakage
Affected Products
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Product | Affected Versions
Mediawiki – AbuseFilter Extension | 1.43.X before 1.43.2
How the Exploit Works
The vulnerability stems from a flaw in the authorization mechanism of the AbuseFilter Extension. An attacker can exploit this flaw by sending specially crafted requests to the affected system. The system fails to properly authenticate these requests, providing the attacker with unauthorized access. From here, the attacker could potentially compromise the system or exfiltrate sensitive data.
Conceptual Example Code
Consider the following
conceptual
example of how the vulnerability might be exploited. In this example, an HTTP request is made that takes advantage of the missing authorization vulnerability.
POST /abusefilter/modify HTTP/1.1
Host: target.example.com
Content-Type: application/json
{
"filter_id": "1",
"actions": { "type": "modify", "parameters": ["new data"] },
"token": "bypass_token"
}In this minimalist example, the attacker sends a request to modify an AbuseFilter, using a bypass token instead of a legitimate session token. The system fails to properly authenticate the request, allowing the attacker to modify the filter and potentially impact the integrity of the system.
Mitigation Guidance
The issue can be mitigated by applying the vendor-supplied patch. Users of affected versions should update to Mediawiki – AbuseFilter Extension 1.43.2 or later. If immediate patching is not possible, the use of a Web Application Firewall (WAF) or Intrusion Detection System (IDS) can provide temporary mitigation. These systems can help detect and block potentially malicious traffic, preventing exploitation of the vulnerability.