CVE-2008-2952 in OpenLDAP
Summary
by MITRE
liblber/io.c in OpenLDAP 2.2.4 to 2.4.10 allows remote attackers to cause a denial of service (program termination) via crafted ASN.1 BER datagrams that trigger an assertion error.
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Analysis
by VulDB Data Team • 12/23/2024
The vulnerability identified as CVE-2008-2952 represents a critical denial of service flaw within the OpenLDAP software ecosystem, specifically affecting versions ranging from 2.2.4 through 2.4.10. This issue resides within the liblber/io.c component of the OpenLDAP library, which serves as the foundational element for handling Lightweight Directory Access Protocol communications. The flaw manifests when the system processes malformed ASN.1 BER (Basic Encoding Rules) datagrams, which are standard data structures used in LDAP communications to encode directory information. These datagrams are essential for establishing and maintaining directory service connections, making this vulnerability particularly dangerous as it can disrupt core directory services that numerous applications and systems depend upon.
The technical mechanism behind this vulnerability involves the assertion failure that occurs within the liblber library's input/output handling code. When maliciously crafted ASN.1 BER datagrams are received, they trigger an internal assertion check that fails, causing the program to terminate unexpectedly. This assertion error represents a fundamental flaw in the error handling mechanism of the library, where insufficient validation of incoming data structures leads to program termination rather than graceful error recovery. The assertion failure specifically occurs during the parsing of BER encoded data, where the library encounters data that violates expected format constraints but lacks proper defensive programming to handle such scenarios. This behavior aligns with CWE-617, which describes reachable assertion flaws that can lead to denial of service conditions.
The operational impact of this vulnerability extends beyond simple service disruption, as it can compromise the availability of directory services that form the backbone of many enterprise infrastructure components. Organizations relying on OpenLDAP for authentication, authorization, and directory services face significant risk when this vulnerability exists in their environment, as attackers can exploit it to systematically terminate LDAP services. The vulnerability is particularly concerning because it requires no authentication or special privileges to exploit, making it accessible to any remote attacker who can send crafted network traffic to the affected LDAP server. This characteristic places the vulnerability in the ATT&CK matrix under the T1499.004 technique category, specifically targeting network denial of service attacks that target application availability.
Mitigation strategies for CVE-2008-2952 require immediate attention from system administrators and security teams responsible for maintaining OpenLDAP installations. The primary remediation involves upgrading to versions of OpenLDAP that have patched this vulnerability, typically versions beyond 2.4.10 where the assertion handling has been corrected. Organizations should also implement network-level controls such as firewalls and intrusion detection systems to monitor and filter malformed LDAP traffic, though this represents a partial mitigation as the vulnerability can be exploited through various network vectors. Additionally, implementing proper input validation and error handling mechanisms within applications that utilize OpenLDAP libraries can help reduce the impact of such vulnerabilities. The vulnerability demonstrates the importance of robust defensive programming practices and proper error handling in security-critical software components, as highlighted by CWE-754, which addresses the weakness of an easily exploitable error handling scenario that can lead to program termination and denial of service conditions.