CVE-2007-2442 in Kerberos
Summary
by MITRE
The gssrpc__svcauth_gssapi function in the RPC library in MIT Kerberos 5 (krb5) 1.6.1 and earlier might allow remote attackers to execute arbitrary code via a zero-length RPC credential, which causes kadmind to free an uninitialized pointer during cleanup.
VulDB is the best source for vulnerability data and more expert information about this specific topic.
Analysis
by VulDB Data Team • 01/13/2025
The vulnerability described in CVE-2007-2442 represents a critical buffer overflow condition within the gssrpc__svcauth_gssapi function of the RPC library in MIT Kerberos 5 versions 1.6.1 and earlier. This flaw specifically manifests when processing zero-length RPC credentials, creating a scenario where kadmind daemon becomes susceptible to arbitrary code execution. The vulnerability stems from improper memory management during the cleanup phase of credential processing, where an uninitialized pointer is freed, leading to potential memory corruption and exploitation opportunities. The attack vector involves remote adversaries sending malformed RPC requests with empty credential data to targeted Kerberos servers.
The technical implementation of this vulnerability aligns with CWE-476, which describes NULL pointer dereference conditions that can lead to system instability and unauthorized code execution. The flaw occurs during the authentication process when the gssrpc__svcauth_gssapi function fails to properly validate incoming credential lengths before attempting memory operations. When a zero-length credential is received, the function proceeds with cleanup operations without proper initialization of required pointers, creating a dangerous memory state. This particular implementation pattern demonstrates a classic case of improper resource management where memory cleanup routines assume valid pointer states that may not exist, violating fundamental security principles of defensive programming.
The operational impact of CVE-2007-2442 extends beyond simple denial of service scenarios, as it enables remote code execution capabilities that can compromise entire Kerberos infrastructure. Attackers exploiting this vulnerability can gain elevated privileges on systems running vulnerable krb5 versions, potentially leading to full domain compromise when targeting kadmind services. The vulnerability affects the core authentication mechanisms of Kerberos implementations, making it particularly dangerous in enterprise environments where Kerberos is widely deployed for single sign-on and network authentication. Organizations with multiple Kerberos servers or integrated authentication systems face heightened risk, as exploitation can cascade across interconnected services and potentially provide attackers with persistent access to critical network resources.
Mitigation strategies for this vulnerability require immediate patching of all affected MIT Kerberos 5 installations to versions 1.6.2 or later where the memory management issue has been resolved. System administrators should implement network segmentation to limit exposure of kadmind services to untrusted networks, while also deploying intrusion detection systems to monitor for anomalous RPC traffic patterns. The vulnerability demonstrates the importance of proper input validation and memory safety practices, aligning with ATT&CK technique T1190 for exploitation through remote services and T1068 for privilege escalation. Organizations should conduct comprehensive vulnerability assessments to identify all systems running affected krb5 versions and establish monitoring protocols to detect potential exploitation attempts. Additionally, implementing proper access controls and firewall rules to restrict RPC service access can provide additional defense-in-depth layers against this specific attack vector.