CVE-2020-9272 in ProFTPD
Summary
by MITRE
ProFTPD 1.3.7 has an out-of-bounds (OOB) read vulnerability in mod_cap via the cap_text.c cap_to_text function.
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Analysis
by VulDB Data Team • 04/02/2024
The vulnerability identified as CVE-2020-9272 represents a critical out-of-bounds read flaw within the ProFTPD 1.3.7 file transfer protocol server implementation. This issue specifically affects the mod_cap module which handles capability-based access control for the FTP daemon. The vulnerability manifests in the cap_to_text function located within the cap_text.c source file, where improper bounds checking allows maliciously crafted input to trigger memory access violations. Such out-of-bounds read conditions typically occur when program code attempts to read memory locations beyond the allocated buffer boundaries, potentially exposing sensitive data or enabling further exploitation techniques.
The technical nature of this vulnerability aligns with CWE-125, which describes out-of-bounds read conditions in software systems. The flaw stems from inadequate input validation within the capability text processing functionality, where the cap_to_text function fails to properly verify buffer limits before performing memory reads. Attackers can exploit this by crafting specially formatted capability strings that cause the function to access memory locations outside the intended buffer scope, potentially leading to information disclosure or system instability. This particular implementation flaw demonstrates poor defensive programming practices where buffer boundaries are not adequately validated before memory operations occur.
From an operational impact perspective, this vulnerability poses significant risks to organizations relying on ProFTPD 1.3.7 for file transfer services. An attacker with access to the FTP service could potentially leverage this out-of-bounds read to extract sensitive information from memory, including authentication credentials, system configurations, or other confidential data. The vulnerability's exploitation could lead to privilege escalation or further attack vectors within the network infrastructure. Given that ProFTPD is widely deployed in enterprise environments, the potential for widespread impact increases significantly, particularly when considering that many organizations may not have updated their systems to address this specific vulnerability.
Mitigation strategies for CVE-2020-9272 should prioritize immediate patch application from the vendor, as the official ProFTPD team has released updates addressing this specific out-of-bounds read condition. Organizations should implement network segmentation and access controls to limit exposure of FTP services to untrusted networks. Additionally, monitoring for anomalous FTP traffic patterns and implementing intrusion detection systems can help identify potential exploitation attempts. The ATT&CK framework categorizes this type of vulnerability under T1071.004 for application layer protocol usage, and organizations should consider implementing defensive measures such as input validation, memory protection mechanisms, and regular security assessments to prevent exploitation. System administrators should also consider disabling unnecessary FTP services and implementing alternative secure file transfer protocols such as SFTP or FTPS where possible to reduce the attack surface.