CVE-2018-8797 in rdesktop
Summary
by MITRE
rdesktop versions up to and including v1.8.3 contain a Heap-Based Buffer Overflow in function process_plane() that results in a memory corruption and probably even a remote code execution.
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Analysis
by VulDB Data Team • 07/06/2023
The vulnerability identified as CVE-2018-8797 represents a critical heap-based buffer overflow within the rdesktop remote desktop protocol client software. This flaw exists specifically within the process_plane() function of rdesktop versions up to and including v1.8.3, making it a significant security concern for organizations relying on remote desktop connectivity. The vulnerability stems from inadequate input validation and memory management practices within the remote desktop protocol implementation, particularly when processing certain graphical plane data structures. The affected software architecture processes remote desktop protocol packets that contain graphical updates, and the buffer overflow occurs when these packets are improperly handled during the rendering process.
The technical implementation of this vulnerability demonstrates a classic heap corruption scenario where maliciously crafted remote desktop protocol packets can trigger memory corruption in the target system. When the process_plane() function receives malformed data, it fails to properly validate the size of incoming buffers before copying data into heap-allocated memory regions. This allows an attacker to overwrite adjacent memory locations, potentially leading to arbitrary code execution. The vulnerability operates at the protocol level, meaning that an attacker could exploit this issue through a specially crafted RDP connection without requiring authentication, though the exact attack vector would depend on how the vulnerable client is deployed and configured. The heap-based nature of the overflow indicates that the attack may be more predictable than stack-based equivalents, as heap memory layout can be influenced through specific exploitation techniques.
The operational impact of CVE-2018-8797 extends beyond simple memory corruption, as it represents a potential path to full system compromise when exploited successfully. Organizations using vulnerable rdesktop versions face risks including unauthorized access, data exfiltration, and persistent backdoor installation. The vulnerability affects any system running affected rdesktop versions that connect to RDP servers, making it particularly dangerous in enterprise environments where remote desktop access is common. Security teams must consider the widespread deployment of rdesktop across various platforms and the potential for this vulnerability to be leveraged in targeted attacks against specific organizations. The remote code execution capability means that attackers could potentially install malware, modify system configurations, or establish persistent access to compromised systems, making this vulnerability particularly severe from a threat perspective.
Mitigation strategies for CVE-2018-8797 primarily focus on immediate software updates and operational security measures. Organizations should prioritize upgrading to rdesktop versions that contain patches addressing this vulnerability, with version 1.8.4 and later recommended for deployment. System administrators should implement network segmentation to limit RDP access to trusted networks and consider disabling RDP connections where possible. The vulnerability aligns with CWE-121, heap-based buffer overflow, and can be mapped to ATT&CK technique T1071.004 for application layer protocol usage. Additionally, implementing network monitoring to detect unusual RDP traffic patterns and deploying intrusion detection systems can help identify potential exploitation attempts. Organizations should also consider alternative remote desktop solutions that have been verified as free from similar vulnerabilities, and establish incident response procedures to address potential exploitation attempts. Regular security assessments and vulnerability scanning should be conducted to ensure that all remote desktop clients remain updated and secure against similar threats.