CVE-2003-0048 in PuTTY
Summary
by MITRE
PuTTY 0.53b and earlier does not clear logon credentials from memory, including plaintext passwords, which could allow attackers with access to memory to steal the SSH credentials.
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Analysis
by VulDB Data Team • 05/24/2019
The vulnerability identified as CVE-2003-0048 affects PuTTY versions 0.53b and earlier, representing a critical security flaw in SSH client implementations that has significant implications for credential protection and memory management. This issue stems from inadequate memory handling practices within the PuTTY application where sensitive authentication data remains accessible in memory even after successful authentication or session termination. The vulnerability specifically targets the storage and retention of plaintext passwords and other authentication credentials within the application's memory space, creating a persistent exposure that extends beyond the normal operational boundaries of secure authentication protocols.
The technical flaw manifests through insufficient memory clearing mechanisms that fail to properly overwrite or release credential data from volatile memory locations. When users authenticate to SSH servers through PuTTY, the application stores the entered credentials in memory for the duration of the session and potentially beyond, without implementing proper secure memory cleanup procedures. This behavior creates a window of opportunity for attackers who gain access to the system's memory space through various attack vectors such as memory dumping techniques, process inspection, or exploitation of other system vulnerabilities. The persistence of credential data in memory means that even after a user has logged out or the application has closed, the plaintext passwords may remain accessible to malicious actors with appropriate privileges or tools.
The operational impact of this vulnerability extends beyond simple credential theft to encompass broader security implications for systems relying on PuTTY for SSH connectivity. Organizations using affected versions of PuTTY face significant risk of unauthorized access to sensitive systems, particularly in environments where memory access might be compromised through malware, insider threats, or system-level attacks. The vulnerability is particularly concerning because it operates at the application level rather than the network level, meaning that even if network traffic is properly secured through encryption, the credentials stored in memory remain exposed. This flaw violates fundamental security principles of credential handling and demonstrates poor secure coding practices that have since been addressed in modern security implementations.
This vulnerability aligns with CWE-115, which addresses the improper handling of credentials in memory, and represents a classic example of insecure data storage in memory management. The attack surface for this vulnerability can be expanded through various exploitation techniques including process memory dumping, debugging tools, and system-level access methods that allow attackers to inspect running processes. From an ATT&CK framework perspective, this vulnerability maps to techniques involving credential access through memory scraping and process injection methods. The remediation strategy requires immediate upgrading to PuTTY versions that implement proper memory clearing mechanisms, including the use of secure memory allocation and deallocation practices that ensure credential data is properly overwritten and released from memory. Organizations should also implement additional security measures such as monitoring for unauthorized memory access attempts and ensuring that systems running PuTTY are protected against other attack vectors that could provide access to process memory.