CVE-2020-7465 in MPD
Summary
by MITRE • 10/06/2020
The L2TP implementation of MPD before 5.9 allows a remote attacker who can send specifically crafted L2TP control packet with AVP Q.931 Cause Code to execute arbitrary code or cause a denial of service (memory corruption).
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Analysis
by VulDB Data Team • 11/16/2020
The vulnerability identified as CVE-2020-7465 affects the Layer 2 Tunneling Protocol implementation within MPD version 5.8 and earlier. This represents a critical security flaw that exists within the network protocol handling mechanisms of the software, specifically targeting the L2TP control packet processing functionality. The vulnerability stems from inadequate input validation and memory management within the protocol stack, creating a potential attack surface that remote adversaries can exploit to compromise system integrity.
The technical flaw manifests when the system processes specifically crafted L2TP control packets containing maliciously formatted AVP Q.931 Cause Code attributes. This particular AVP format is part of the Q.931 signaling protocol used in telecommunications networks, and when improperly handled by the MPD software, it triggers memory corruption vulnerabilities. The flaw operates at the protocol parsing layer where the system fails to properly validate the length and content of the Cause Code attribute before attempting to process it, leading to potential buffer overflows or other memory corruption conditions.
The operational impact of this vulnerability extends beyond simple denial of service scenarios to encompass full arbitrary code execution capabilities. Remote attackers can leverage this weakness to inject malicious code into the target system, potentially gaining unauthorized access to network resources or executing malicious payloads. The memory corruption aspects of the vulnerability can also lead to system crashes, making the affected service unavailable to legitimate users and potentially enabling further exploitation attempts. This vulnerability directly impacts network infrastructure devices that rely on MPD for L2TP tunnel management and security.
Mitigation strategies should focus on immediate software updates to MPD version 5.9 or later, which contain patches addressing the memory handling and input validation issues. Network administrators should also implement monitoring solutions to detect unusual L2TP control packet patterns that might indicate exploitation attempts. The vulnerability aligns with CWE-121, which addresses stack-based buffer overflow conditions, and potentially CWE-122 for heap-based buffer overflows. From an ATT&CK framework perspective, this vulnerability maps to T1059 for command and control execution and T1499 for network disruption, as it enables both arbitrary code execution and denial of service capabilities that can compromise network availability and integrity.