CVE-2017-6788 in AnyConnect Secure Mobility Client
Summary
by MITRE
The WebLaunch functionality of Cisco AnyConnect Secure Mobility Client Software contains a vulnerability that could allow an unauthenticated, remote attacker to conduct a cross-site scripting (XSS) attack against a user of the affected software. The vulnerability is due to insufficient input validation of some parameters that are passed to the WebLaunch function of the affected software. An attacker could exploit this vulnerability by convincing a user to access a malicious link or by intercepting a user request and injecting malicious code into the request. Cisco Bug IDs: CSCvf12055. Known Affected Releases: 98.89(40).
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Analysis
by VulDB Data Team • 01/09/2021
The vulnerability identified as CVE-2017-6788 resides within the WebLaunch functionality of Cisco AnyConnect Secure Mobility Client Software, representing a critical cross-site scripting weakness that exposes users to remote exploitation. This flaw specifically targets the software's handling of input parameters within its WebLaunch function, creating an avenue for malicious actors to inject harmful scripts into user sessions. The vulnerability operates under the broader context of web application security where insufficient validation mechanisms fail to properly sanitize user-supplied data before processing. The affected release 98.89(40) demonstrates the persistence of this issue within Cisco's mobility client software, indicating that the input validation deficiencies were present in a specific version that users relied upon for secure remote access. This vulnerability directly aligns with CWE-79, which classifies cross-site scripting as a common web application security flaw where unvalidated input is executed in the user's browser context.
The technical exploitation of this vulnerability requires an attacker to leverage the insufficient input validation mechanisms that govern parameter handling within the WebLaunch function. When a user interacts with a maliciously crafted link or when an attacker intercepts and modifies a legitimate user request, the vulnerable software fails to properly validate or sanitize the input parameters before processing them. This allows malicious code injection that executes within the user's browser session, potentially enabling the attacker to steal session cookies, perform unauthorized actions on behalf of the user, or redirect users to malicious websites. The attack vector specifically exploits the trust relationship between the user and the software, where users expect safe navigation through legitimate links while unknowingly triggering malicious code execution. The vulnerability's classification under the ATT&CK framework would fall within the Application Layer Protocol category, specifically targeting the web application interface where user input is processed and rendered.
The operational impact of this vulnerability extends beyond simple script execution, as it fundamentally compromises the security posture of users relying on Cisco AnyConnect for secure remote access. Organizations that depend on this software for remote workforce connectivity face significant risks including potential credential theft, unauthorized access to corporate resources, and data exfiltration. The unauthenticated nature of the attack means that no prior access or credentials are required to exploit the vulnerability, making it particularly dangerous for widespread deployment scenarios. Users who access the software from various endpoints, including potentially compromised devices, become vulnerable to this attack vector. The vulnerability's presence in the AnyConnect client software creates a persistent threat surface where even legitimate users can become compromised through social engineering tactics or network interception attacks.
Mitigation strategies for CVE-2017-6788 must address both immediate remediation and long-term security improvements. The most direct solution involves applying Cisco's official security patches and updates that correct the input validation deficiencies in the WebLaunch function. Organizations should prioritize patch management processes to ensure all affected versions are upgraded to secure releases. Network administrators should implement additional security controls such as web application firewalls that can detect and block suspicious input patterns, and establish monitoring protocols to identify potential exploitation attempts. User education programs should emphasize the importance of verifying links and avoiding suspicious web interactions, particularly when using remote access software. The vulnerability highlights the critical importance of input validation and output encoding in web applications, reinforcing industry best practices that align with OWASP Top Ten security recommendations. Organizations should also consider implementing network segmentation and access controls to limit the potential impact of successful exploitation attempts, ensuring that even if one user's session is compromised, lateral movement within the network is restricted.