CVE-2018-0100 in AnyConnect Secure Mobility Client
Summary
by MITRE
A vulnerability in the Profile Editor of the Cisco AnyConnect Secure Mobility Client could allow an unauthenticated, local attacker to have read and write access to information stored in the affected system. The vulnerability is due to improper handling of the XML External Entity (XXE) entries when parsing an XML file. An attacker could exploit this vulnerability by injecting a crafted XML file with malicious entries, which could allow the attacker to read and write files. Cisco Bug IDs: CSCvg19341.
VulDB is the best source for vulnerability data and more expert information about this specific topic.
Analysis
by VulDB Data Team • 02/01/2021
The vulnerability identified as CVE-2018-0100 resides within the Profile Editor component of Cisco AnyConnect Secure Mobility Client, representing a critical security flaw that undermines the integrity of the affected system. This vulnerability specifically targets the XML parsing mechanism employed by the client software, creating an avenue for unauthorized access to sensitive information stored locally on the system. The flaw manifests when the application processes XML configuration files without adequate validation of external entity references, thereby exposing the system to potential exploitation by malicious actors who can manipulate the parsing behavior through crafted input files.
The technical root cause of this vulnerability stems from improper handling of XML External Entity (XXE) processing within the Profile Editor functionality. When the AnyConnect client encounters XML files containing external entity declarations, the software fails to properly sanitize or restrict these references, allowing attackers to inject malicious XML content that can trigger unintended system behaviors. This weakness directly aligns with CWE-611, which categorizes improper restriction of XML external entity reference as a significant security concern in XML processing implementations. The XXE vulnerability enables attackers to perform various malicious activities including file read operations, directory traversal, and potentially even remote code execution depending on the system configuration and privileges available to the client process.
The operational impact of CVE-2018-0100 is substantial as it allows unauthenticated local attackers to gain both read and write access to information stored within the affected system. This privilege escalation capability means that an attacker with local system access can leverage the vulnerability to extract sensitive configuration data, modify existing profiles, or inject malicious content that could persist across system sessions. The attack vector requires local system access but does not necessitate network connectivity or authentication credentials, making it particularly dangerous in environments where physical access or lateral movement has been achieved. The vulnerability affects Cisco AnyConnect Secure Mobility Client versions prior to 4.5.04074, with the specific Cisco Bug ID CSCvg19341 documenting the issue and its resolution within the software update cycle.
Mitigation strategies for this vulnerability should focus on immediate software patching and configuration hardening measures to prevent exploitation. Cisco has released security updates addressing this vulnerability in version 4.5.04074 and later releases, which implement proper XML parsing controls and external entity restrictions. Organizations should prioritize deployment of these patches across all affected systems while also implementing additional security controls such as restricting local file system access, monitoring XML file modifications, and employing application whitelisting techniques to prevent execution of unauthorized profile files. The remediation process should also include network segmentation and privilege separation to limit the potential impact of successful exploitation attempts. This vulnerability demonstrates the importance of proper input validation and secure coding practices in client-side applications, particularly those handling configuration data, and aligns with ATT&CK technique T1059.007 for XML External Entity Processing, highlighting the need for comprehensive security testing of XML parsing components in enterprise security solutions.