CVE-2018-8798 in rdesktop
Summary
by MITRE
rdesktop versions up to and including v1.8.3 contain an Out-Of-Bounds Read in function rdpsnd_process_ping() that results in an information leak.
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Analysis
by VulDB Data Team • 07/06/2023
The vulnerability identified as CVE-2018-8798 affects rdesktop versions up to and including v1.8.3, representing a critical out-of-bounds read condition within the rdpsnd_process_ping() function. This flaw manifests in the remote desktop protocol client implementation, where improper input validation leads to memory access violations that can expose sensitive data from the application's memory space. The vulnerability specifically impacts the audio redirection component of rdesktop, which handles multimedia data streams during remote desktop sessions.
The technical implementation of this vulnerability stems from inadequate bounds checking within the rdpsnd_process_ping() function, which processes ping responses for audio streaming capabilities. When processing malformed or unexpected input data, the function fails to validate array indices or buffer boundaries before accessing memory locations, creating a scenario where arbitrary memory locations may be read. This type of flaw falls under CWE-129, which specifically addresses insufficient validation of the length of input data, and CWE-125, which covers out-of-bounds read conditions. The vulnerability demonstrates characteristics consistent with ATT&CK technique T1059.007, where adversaries may exploit memory corruption vulnerabilities to gain unauthorized access to system information.
The operational impact of CVE-2018-8798 extends beyond simple information disclosure, as the out-of-bounds read can potentially expose sensitive data such as cryptographic keys, session tokens, or other confidential information stored in adjacent memory locations. Attackers exploiting this vulnerability could leverage the information leak to reconstruct portions of the application's memory state, potentially leading to further exploitation opportunities including privilege escalation or credential compromise. The vulnerability affects users who employ rdesktop for remote desktop connections, particularly in enterprise environments where audio redirection features are utilized, making it a significant concern for organizations relying on remote access solutions.
Mitigation strategies for this vulnerability require immediate patching of affected rdesktop installations to versions that include proper bounds checking and input validation within the rdpsnd_process_ping() function. System administrators should also implement network segmentation and access controls to limit exposure of affected systems, while monitoring for unusual network traffic patterns that might indicate exploitation attempts. The fix typically involves adding proper validation checks for buffer sizes and array indices before memory access operations, ensuring that all input data is properly sanitized before processing. Organizations should also consider implementing network-based intrusion detection systems that can identify and block malicious traffic patterns associated with this specific vulnerability. Additionally, regular security assessments and vulnerability scanning should be conducted to identify other potential memory corruption issues within similar remote desktop implementations.