CVE-2010-4148 in AnyConnect
Summary
by MITRE
Directory traversal vulnerability in AnyConnect 1.2.3.0, and possibly earlier, allows remote FTP servers to write arbitrary files via a "..\" (dot dot backslash) in a filename.
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Analysis
by VulDB Data Team • 02/08/2019
The vulnerability identified as CVE-2010-4148 represents a critical directory traversal flaw within Cisco AnyConnect client software version 1.2.3.0 and potentially earlier releases. This security weakness stems from inadequate input validation mechanisms that fail to properly sanitize filename inputs received from remote FTP servers during file transfer operations. The vulnerability specifically manifests when the client processes filenames containing "..\" sequences, which are commonly used in directory traversal attacks to navigate outside of intended directories and access restricted file systems. The flaw enables malicious FTP servers to exploit this weakness and write arbitrary files to locations outside the expected download directories, potentially leading to unauthorized system modifications and privilege escalation.
From a technical perspective, this vulnerability operates at the application layer and exploits a fundamental flaw in how the AnyConnect client handles file path resolution. The "..\" sequence when processed by the vulnerable software can cause the client to interpret the filename as attempting to traverse up the directory tree, bypassing normal file system access controls. This behavior violates the principle of least privilege and allows remote attackers to write files to arbitrary locations on the target system. The vulnerability falls under the Common Weakness Enumeration category CWE-22, which specifically addresses directory traversal or path traversal issues. The attack vector requires a remote FTP server that can be controlled by an attacker, making this a remote code execution vulnerability that can be exploited from outside the corporate network perimeter.
The operational impact of CVE-2010-4148 extends beyond simple file system manipulation, as it can potentially enable attackers to deploy malicious payloads, modify system configuration files, or establish persistent access points within the network. When combined with other exploitation techniques, this vulnerability could allow attackers to escalate privileges and gain deeper access to network resources. The attack requires minimal user interaction since it operates through the normal file transfer process, making it particularly dangerous in environments where users frequently download files from external sources. Organizations using AnyConnect clients in enterprise environments face significant risk, as this vulnerability could be exploited to compromise endpoints and potentially escalate to broader network attacks. The vulnerability also aligns with ATT&CK technique T1059, which covers command and scripting interpreter usage, as successful exploitation could enable attackers to execute arbitrary commands through the written files.
Mitigation strategies for this vulnerability should include immediate patching of AnyConnect client software to versions that address the directory traversal flaw. Organizations should also implement network segmentation and firewall rules that restrict access to FTP servers from untrusted networks, particularly where these servers might be compromised. Additional protective measures include disabling unnecessary FTP functionality on client systems and implementing strict file access controls on systems where AnyConnect is deployed. Security monitoring should focus on detecting unusual file creation patterns and unauthorized modifications to system directories. Network administrators should also consider implementing intrusion detection systems that can identify and alert on suspicious FTP traffic patterns. The vulnerability highlights the importance of proper input validation and secure coding practices in client-side applications, particularly those handling file operations from external sources. Organizations should also conduct regular vulnerability assessments to identify similar weaknesses in other network security tools and client applications.