Source: cve@mitre.org
Multiple vulnerabilities in the OpenSSL ASN.1 parser, as used in Novell iManager 2.0.2, allows remote attackers to cause a denial of service (NULL pointer dereference) via crafted packets, as demonstrated by "OpenSSL ASN.1 brute forcer." NOTE: this issue might overlap CVE-2004-0079, CVE-2004-0081, or CVE-2004-0112.
OpenSSL's ASN.1 parser within Novell iManager 2.0.2 is vulnerable to a denial-of-service (DoS) attack. Attackers can craft malicious packets to trigger a NULL pointer dereference, crashing the iManager service and potentially disrupting critical network management functions. This vulnerability allows for easy exploitation and can lead to significant operational impact.
Step 1: Packet Crafting: The attacker crafts a malicious packet containing a specially crafted ASN.1 structure. This structure is designed to exploit a vulnerability in the OpenSSL ASN.1 parser.
Step 2: Packet Delivery: The attacker sends the crafted packet to a vulnerable Novell iManager 2.0.2 server. This is likely achieved over a network connection, potentially using a protocol like LDAP or HTTPS, depending on how iManager is configured.
Step 3: Parsing Trigger: The iManager server, upon receiving the packet, attempts to parse the ASN.1 structure using the vulnerable OpenSSL library.
Step 4: Vulnerability Exploitation: The ASN.1 parser encounters the malformed structure and, due to a lack of proper input validation or incorrect memory management, attempts to dereference a NULL pointer.
Step 5: Denial of Service: The NULL pointer dereference causes the iManager process to crash, resulting in a denial-of-service condition. The service becomes unavailable, disrupting network management operations.
The vulnerability stems from flaws in OpenSSL's ASN.1 parser, specifically within its handling of malformed or excessively large ASN.1 structures. The parser, when processing these crafted packets, fails to properly validate input data, leading to a NULL pointer dereference. This occurs when the code attempts to access memory at address zero, which is an invalid memory location. The root cause is likely related to insufficient bounds checking or incorrect memory allocation within the parsing routines, allowing for an out-of-bounds read or write. The 'OpenSSL ASN.1 brute forcer' mentioned in the description suggests that the vulnerability can be triggered by sending a series of crafted ASN.1 packets, potentially exploiting a logic error in how the parser handles nested structures or specific ASN.1 types. The overlap with other CVEs (CVE-2004-0079, CVE-2004-0081, CVE-2004-0112) indicates a broader issue with OpenSSL's ASN.1 parsing implementation, with similar vulnerabilities potentially arising from related code paths.
Due to the age of the vulnerability, it's possible that various threat actors, including both state-sponsored and financially motivated groups, could have incorporated exploits into their toolkits. The ease of exploitation makes it attractive for opportunistic attacks. There is no specific APT attribution available from the provided information. This vulnerability is not listed on the CISA KEV catalog.
Network Intrusion Detection Systems (NIDS) can be configured to detect malicious ASN.1 packets by inspecting network traffic for specific patterns or characteristics associated with the exploit.
Security Information and Event Management (SIEM) systems can be used to analyze logs for unusual activity, such as repeated connection attempts or service crashes related to iManager.
Forensic analysis of system logs (e.g., system event logs, application logs) can reveal crashes or errors related to the iManager service, potentially indicating exploitation. Look for crash dumps or core files.
Monitor network traffic for unusual traffic patterns, particularly to ports used by iManager (e.g., LDAP, HTTPS).
Implement host-based intrusion detection systems (HIDS) to monitor for suspicious file modifications or process behavior.
Upgrade to a patched version of Novell iManager that includes a fix for the OpenSSL ASN.1 parsing vulnerabilities. This is the primary and most effective remediation step.
If upgrading is not immediately possible, apply any available security patches or hotfixes provided by Novell for iManager 2.0.2.
Implement network segmentation to isolate the iManager server from other critical network resources, limiting the impact of a successful exploit.
Implement a Web Application Firewall (WAF) or other network security devices to filter malicious traffic.
Regularly scan the network for vulnerable systems and ensure that all systems are patched promptly.
Monitor network traffic and system logs for suspicious activity, such as repeated connection attempts or service crashes.