CVE-2008-2357 in mtr
Summary
by MITRE
Stack-based buffer overflow in the split_redraw function in split.c in mtr before 0.73, when invoked with the -p (aka --split) option, allows remote attackers to execute arbitrary code via a crafted DNS PTR record. NOTE: it could be argued that this is a vulnerability in the ns_name_ntop function in resolv/ns_name.c in glibc and the proper fix should be in glibc; if so, then this should not be treated as a vulnerability in mtr.
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Analysis
by VulDB Data Team • 08/10/2019
The vulnerability identified as CVE-2008-2357 represents a critical stack-based buffer overflow affecting the mtr network diagnostic tool version 0.72 and earlier. This flaw manifests within the split_redraw function located in the split.c source file, specifically when the tool is executed with the -p or --split command-line option. The vulnerability creates a pathway for remote code execution through manipulation of DNS PTR records, making it particularly dangerous in network monitoring contexts where mtr is commonly deployed.
The technical mechanism of this vulnerability involves improper input validation within the mtr application's handling of DNS PTR records. When mtr processes these records using the split functionality, the application fails to properly bounds-check data received from network sources, allowing an attacker to craft malicious PTR records that exceed the allocated buffer space. This buffer overflow occurs in the stack memory region, where the application's memory management fails to account for potentially oversized input data, leading to memory corruption that can be exploited to overwrite critical program execution elements.
The operational impact of this vulnerability extends beyond simple remote code execution, as it fundamentally compromises the integrity and availability of systems running vulnerable versions of mtr. Network administrators who rely on mtr for monitoring and diagnostics become potential targets, since attackers can exploit this vulnerability to gain unauthorized access to systems where mtr is executed with elevated privileges. The attack vector through DNS PTR records makes this particularly concerning in environments where DNS services are not properly secured or monitored, as the vulnerability can be triggered through legitimate network traffic without requiring direct system access.
The vulnerability's classification aligns with CWE-121, which describes stack-based buffer overflow conditions where insufficient bounds checking allows attackers to overwrite adjacent stack memory. From an adversarial perspective, this vulnerability maps to ATT&CK technique T1059.007 for command and control communication, as attackers could leverage the remote code execution capability to establish persistent access. The issue demonstrates how seemingly benign network diagnostic tools can become attack vectors when they fail to properly validate external input, highlighting the importance of robust input sanitization in network applications.
While the vulnerability description notes that some argue the root cause lies within glibc's ns_name_ntop function, this does not diminish the validity of treating it as a vulnerability in mtr itself. The mtr application's responsibility includes proper handling of all inputs regardless of their source, and the application should not rely on external libraries to provide adequate protection against buffer overflows. The proper mitigation approach involves implementing bounds checking within mtr's own codebase, specifically addressing the input handling in the split_redraw function, rather than expecting external dependencies to provide sufficient protection. This vulnerability underscores the principle that applications should not trust any external input and must implement proper validation and sanitization regardless of the underlying library implementations.
The remediation strategy for CVE-2008-2357 requires immediate upgrading to mtr version 0.73 or later, which contains the necessary patches to address the buffer overflow condition. System administrators should also implement network segmentation and monitoring to detect anomalous DNS PTR record traffic that might indicate exploitation attempts. Additionally, the vulnerability serves as a reminder of the importance of regularly updating network diagnostic tools and conducting security assessments of network infrastructure components that handle external input. The incident highlights the need for comprehensive input validation practices and proper memory management in network applications, particularly those that operate in environments where they may encounter untrusted network data.