CVE-2018-20737 in API Manager
Summary
by MITRE
An issue was discovered in WSO2 API Manager 2.1.0 and 2.6.0. Reflected XSS exists in the carbon part of the product.
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Analysis
by VulDB Data Team • 08/03/2023
The vulnerability identified as CVE-2018-20737 represents a significant security flaw in WSO2 API Manager versions 2.1.0 and 2.6.0, specifically within the carbon administrative component of the platform. This issue manifests as a reflected cross-site scripting vulnerability that allows malicious actors to inject and execute arbitrary JavaScript code within the context of a victim's browser session. The carbon part of WSO2 API Manager serves as the core administrative interface and management console, making this vulnerability particularly dangerous as it directly impacts the system's administrative capabilities and user session security.
The technical implementation of this reflected XSS vulnerability stems from inadequate input validation and output encoding mechanisms within the carbon administrative interface. When users interact with certain parameters in the web application's URL or form inputs, the application fails to properly sanitize or encode user-supplied data before rendering it in web responses. This allows attackers to craft malicious URLs or form submissions containing script payloads that get executed when other users view the affected pages. The reflected nature of the vulnerability means that the malicious script is reflected off the web server back to the victim's browser, making it particularly effective for phishing attacks and session hijacking attempts. This vulnerability directly maps to CWE-79 which defines cross-site scripting as a weakness where untrusted data is sent to a web browser without proper validation or encoding.
The operational impact of this vulnerability extends beyond simple data theft or session manipulation, as it provides attackers with the capability to escalate privileges within the administrative interface. An attacker who successfully exploits this vulnerability could potentially access sensitive configuration data, modify user permissions, or even gain full administrative control over the API management platform. The attack surface is particularly concerning given that the carbon administrative interface typically contains sensitive information about API deployments, user management, and system configurations that could be leveraged for further attacks against the broader infrastructure. This vulnerability also aligns with ATT&CK technique T1059.007 which involves the use of script-based attacks to execute malicious code in web browsers, and T1566 which encompasses social engineering techniques that leverage reflected XSS to manipulate users into executing malicious payloads.
Organizations utilizing WSO2 API Manager versions 2.1.0 and 2.6.0 should immediately implement mitigations including comprehensive input validation, output encoding, and the implementation of Content Security Policies to prevent execution of unauthorized scripts. The most effective remediation involves upgrading to patched versions of WSO2 API Manager where the input sanitization mechanisms have been properly implemented. Additionally, network-level protections such as web application firewalls can provide additional defense-in-depth measures while the permanent fix is being implemented. Security teams should also conduct thorough penetration testing to identify any potential exploitation attempts and monitor for suspicious user behavior or unauthorized access patterns that may indicate successful exploitation of this vulnerability.