CVE-2010-2444 in MaraDNS
Summary
by MITRE
parse/Csv2_parse.c in MaraDNS 1.3.03, and other versions before 1.4.03, does not properly handle hostnames that do not end in a "." (dot) character, which allows remote attackers to cause a denial of service (NULL pointer dereference) via a crafted csv2 zone file.
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Analysis
by VulDB Data Team • 09/18/2021
The vulnerability identified as CVE-2010-2444 affects MaraDNS version 1.3.03 and earlier, representing a critical denial of service flaw in the CSV2 zone file parsing functionality. This issue stems from improper handling of hostnames within DNS zone files that lack trailing dot characters, creating a scenario where remote attackers can manipulate the parsing process to trigger system instability. The vulnerability specifically resides in the parse/Csv2_parse.c component of the MaraDNS software, which is responsible for processing CSV2 formatted zone files used in DNS server configurations.
The technical flaw manifests as a NULL pointer dereference condition when the parser encounters hostnames without trailing dots during CSV2 zone file processing. This occurs because the parsing logic fails to properly validate or normalize hostname formats before attempting to access memory locations that may not be properly initialized. The absence of proper input sanitization allows maliciously crafted zone files to contain hostnames that do not conform to standard DNS naming conventions, specifically those lacking the required trailing dot termination that indicates the root zone. When the parser attempts to process such malformed entries, it dereferences a NULL pointer, leading to immediate system termination or crash.
The operational impact of this vulnerability extends beyond simple service disruption to potentially compromise the entire DNS resolution infrastructure managed by affected MaraDNS servers. Remote attackers can exploit this weakness by uploading or modifying CSV2 zone files with specially crafted hostnames that lack trailing dots, thereby triggering the NULL pointer dereference and causing the DNS server to become unresponsive. This denial of service condition affects all systems running vulnerable versions of MaraDNS, potentially disrupting network services that depend on DNS resolution for proper operation. The vulnerability is particularly concerning in environments where DNS servers handle critical infrastructure services or where automated zone file updates occur without proper validation mechanisms.
Mitigation strategies for this vulnerability require immediate upgrading to MaraDNS version 1.4.03 or later, which contains the necessary patches to properly handle hostname validation and prevent NULL pointer dereference conditions. System administrators should implement strict input validation for all CSV2 zone files, ensuring that hostnames are properly formatted with trailing dots before being processed by the DNS server. Additionally, network segmentation and monitoring solutions should be deployed to detect unusual patterns in zone file modifications that might indicate exploitation attempts. The vulnerability aligns with CWE-476, which addresses NULL pointer dereference conditions, and represents a classic example of insufficient input validation that can be exploited through crafted data input to cause system instability. Organizations should also consider implementing automated patch management processes to ensure timely deployment of security updates and maintain comprehensive logging of DNS configuration changes for forensic analysis purposes.