CVE-2008-5904 in xrdp
Summary
by MITRE
The rdp_rdp_process_color_pointer_pdu function in rdp/rdp_rdp.c in xrdp 0.4.1 and earlier allows remote RDP servers to have an unknown impact via input data that sets crafted values for certain length variables, leading to a buffer overflow.
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Analysis
by VulDB Data Team • 12/25/2024
The vulnerability identified as CVE-2008-5904 represents a critical buffer overflow condition within the xrdp remote desktop protocol implementation. This flaw exists in the rdp_rdp_process_color_pointer_pdu function located in the rdp/rdp_rdp.c source file of xrdp versions 0.4.1 and earlier. The vulnerability manifests when remote RDP servers transmit specially crafted input data containing malformed length variables that trigger memory corruption during pointer processing operations.
The technical implementation of this vulnerability stems from insufficient input validation within the RDP protocol processing layer. When the rdp_rdp_process_color_pointer_pdu function receives pointer data from a remote server, it fails to properly validate the length parameters associated with color pointer attributes. This validation gap allows attackers to manipulate the length fields in the incoming data stream, causing the function to allocate insufficient buffer space for processing the pointer information. The resulting buffer overflow occurs when the system attempts to write data beyond the allocated memory boundaries, potentially corrupting adjacent memory regions and creating opportunities for arbitrary code execution.
The operational impact of this vulnerability extends beyond simple memory corruption, as it provides remote attackers with potential pathways for privilege escalation and system compromise. Attackers exploiting this vulnerability could execute malicious code within the context of the affected xrdp service, potentially gaining unauthorized access to systems running vulnerable versions. The vulnerability affects organizations that rely on xrdp for remote desktop services, particularly those implementing older versions that have not received security updates. The remote nature of the exploit means that attackers do not require local access to the system, making it a significant concern for networked environments where RDP services are exposed to external networks.
Security professionals should recognize this vulnerability as a classic example of a buffer overflow that aligns with CWE-121, which describes the condition where a program writes data past the end of a fixed-length buffer. The attack pattern associated with this vulnerability follows typical remote exploitation techniques documented in the MITRE ATT&CK framework under the T1059.007 sub-technique for command and scripting interpreter. Organizations should implement immediate mitigations including upgrading to patched versions of xrdp, implementing network segmentation to limit RDP access, and deploying intrusion detection systems to monitor for suspicious RDP traffic patterns. The vulnerability underscores the critical importance of input validation and proper memory management in network protocol implementations, particularly those handling untrusted data from remote sources.