CVE-2018-19530 in HTTL
Summary
by MITRE
HTTL (aka Hyper-Text Template Language) through 1.0.11 allows remote command execution because the decodeXml function uses XStream unsafely when configured with an xml.codec=httl.spi.codecs.XstreamCodec setting.
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Analysis
by VulDB Data Team • 06/11/2023
CVE-2018-19530 represents a critical remote code execution vulnerability affecting HTTL (Hyper-Text Template Language) versions through 1.0.11. This vulnerability stems from unsafe usage of the XStream library within the decodeXml function when configured with the specific xml.codec=httl.spi.codecs.XstreamCodec setting. The flaw exists at the core of how HTTL processes XML data, creating a dangerous attack surface that allows remote adversaries to execute arbitrary commands on affected systems. The vulnerability is classified under CWE-470 as "Use of Externally Controllable Input in a Command" and aligns with ATT&CK technique T1059.007 for command and scripting interpreter. The XStream library, while powerful for XML serialization, has a well-documented history of vulnerabilities when used without proper security configurations, particularly when deserializing untrusted data. When HTTL configures XStream with the XstreamCodec, it enables unsafe deserialization patterns that bypass standard security controls and allow attackers to craft malicious XML payloads that execute system commands. The operational impact of this vulnerability is severe as it enables attackers to gain full system control without requiring authentication, making it particularly dangerous in web applications and services that process user-provided XML content. Attackers can exploit this by submitting specially crafted XML data that, when processed by the vulnerable decodeXml function, triggers XStream to deserialize malicious objects containing executable code. The vulnerability demonstrates poor input validation and unsafe deserialization practices that violate fundamental security principles. Organizations using HTTL in production environments face significant risk, as this vulnerability can be exploited through various attack vectors including web forms, API endpoints, or any interface that accepts XML input. The exploitation requires minimal privileges and can result in complete system compromise, data exfiltration, and persistence mechanisms being established. Security mitigations include upgrading to patched versions of HTTL, implementing proper input validation, disabling unsafe XStream configurations, and employing application firewalls to filter malicious XML content. Additionally, organizations should consider implementing sandboxing mechanisms and restricting network access to prevent lateral movement if exploitation occurs. The vulnerability serves as a stark reminder of the dangers associated with unsafe deserialization patterns and the importance of following secure coding practices, particularly when integrating third-party libraries that handle object serialization and deserialization. This issue highlights the critical need for security awareness training and code reviews focusing on serialization security to prevent similar vulnerabilities in other applications.