CVE-2012-2494 in AnyConnect Secure Mobility Client
Summary
by MITRE
The VPN downloader implementation in the WebLaunch feature in Cisco AnyConnect Secure Mobility Client 2.x before 2.5 MR6 and 3.x before 3.0 MR8 does not compare the timestamp of offered software to the timestamp of installed software, which allows remote attackers to force a version downgrade by using (1) ActiveX or (2) Java components to offer signed code that corresponds to an older software release, aka Bug ID CSCtw48681.
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Analysis
by VulDB Data Team • 12/04/2021
The vulnerability described in CVE-2012-2494 represents a critical security flaw in Cisco AnyConnect Secure Mobility Client's WebLaunch feature implementation. This vulnerability affects versions 2.x before 2.5 MR6 and 3.x before 3.0 MR8, creating a persistent risk for organizations relying on Cisco's secure remote access solutions. The flaw resides in the VPN downloader component that handles software updates and installations, specifically failing to validate timestamp comparisons between offered and installed software versions. This oversight creates a significant attack surface that adversaries can exploit to manipulate the update process and potentially downgrade client software to older, more vulnerable versions.
The technical implementation of this vulnerability stems from the absence of proper version validation mechanisms within the WebLaunch feature's software downloader. When the AnyConnect client receives software offers through ActiveX or Java components, it should verify that the timestamp of the offered software is newer than the currently installed version. However, the flaw allows attackers to bypass this critical check by providing signed code that corresponds to an older software release. This downgrade attack vector specifically targets the timestamp comparison logic, which is designed to prevent installation of older software versions but fails to properly enforce this constraint. The vulnerability aligns with CWE-226, which describes "Sensitive Information Exposure Through Software Version" and represents a failure in proper version control mechanisms.
The operational impact of this vulnerability extends beyond simple version downgrading, creating potential security implications that could compromise entire network access infrastructures. Attackers exploiting this flaw can force clients to install older versions of the AnyConnect client that may contain known vulnerabilities, backdoors, or weakened security controls. The use of ActiveX or Java components as attack vectors demonstrates how legacy web technologies can be weaponized to bypass modern security controls, particularly when these components are not properly sandboxed or validated against the client's update mechanisms. This vulnerability can be particularly dangerous in enterprise environments where security policies rely on maintaining updated client software versions to protect against known exploits and ensure proper encryption protocols.
Organizations should implement multiple layers of mitigation to address this vulnerability effectively. Immediate remediation involves updating affected AnyConnect client versions to the patched releases that properly implement timestamp comparisons and version validation. Network administrators should also consider implementing strict controls over ActiveX and Java component usage, particularly in environments where these technologies are not essential for legitimate business operations. The mitigation strategy should include monitoring for unauthorized software installations and implementing network-based controls that prevent downgrading attacks. This vulnerability's characteristics align with ATT&CK technique T1068, which covers "Exploitation for Privilege Escalation," and T1566, which covers "Phishing for Information," as attackers may need to craft convincing phishing campaigns to deliver the malicious ActiveX or Java components that trigger the downgrade process.