CVE-2003-1455 in PPTP Server
Summary
by MITRE
Multiple buffer overflows in the launch_bcrelay function in pptpctrl.c in PoPToP 1.1.4-b1 through PoPToP 1.1.4-b3 allow local users to execute arbitrary code.
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Analysis
by VulDB Data Team • 07/05/2017
The vulnerability identified as CVE-2003-1455 represents a critical security flaw in the PoPToP Point-to-Point Tunneling Protocol implementation that affects versions 1.1.4-b1 through 1.1.4-b3. This issue manifests as multiple buffer overflows within the launch_bcrelay function located in the pptpctrl.c source file, creating a significant attack surface that could be exploited by local adversaries to gain unauthorized code execution privileges. The PoPToP software serves as a popular open-source implementation for establishing ppp connections over ip networks, making this vulnerability particularly concerning for systems relying on this protocol for remote access and network connectivity.
The technical implementation of this vulnerability stems from inadequate input validation and memory management practices within the launch_bcrelay function. When processing certain input parameters or configuration values, the function fails to properly bounds-check array accesses or string operations, leading to memory corruption that can be leveraged to overwrite adjacent memory locations. This type of flaw falls under the CWE-121 buffer overflow category, specifically classified as a stack-based buffer overflow that can potentially be exploited to overwrite return addresses and function pointers. The vulnerability's exploitation requires local system access, making it a local privilege escalation issue rather than a remote attack vector, yet it still presents significant risks for systems where local users might have elevated privileges or where the service runs with elevated permissions.
The operational impact of this vulnerability extends beyond simple code execution capabilities as it enables attackers to potentially gain elevated privileges on affected systems. Local users who can successfully exploit this vulnerability may be able to execute arbitrary code with the privileges of the PoPToP service or the user account under which it operates. This could lead to complete system compromise, data exfiltration, or the establishment of persistent backdoors. The vulnerability's presence in widely deployed network infrastructure components makes it particularly dangerous for enterprise environments where PoPToP is used for remote access solutions, as it could be exploited to gain unauthorized access to corporate networks through compromised endpoints.
Mitigation strategies for this vulnerability should include immediate patching of affected PoPToP installations to versions that address the buffer overflow conditions in the launch_bcrelay function. System administrators should also implement network segmentation and access controls to limit local user privileges where PoPToP services are deployed, following the principle of least privilege as recommended by cybersecurity frameworks. Additionally, monitoring systems should be configured to detect unusual process execution patterns or unauthorized access attempts to network services. The vulnerability demonstrates the importance of input validation and proper memory management practices, aligning with ATT&CK technique T1059.007 for command and script interpreter execution and T1068 for exploit for privilege escalation. Organizations should also consider implementing application whitelisting policies and regular security assessments to identify similar memory corruption vulnerabilities in other network services and applications.