CVE-2018-19213 in Netwide Assembler
Summary
by MITRE
Netwide Assembler (NASM) through 2.14rc16 has memory leaks that may lead to DoS, related to nasm_malloc in nasmlib/malloc.c.
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Analysis
by VulDB Data Team • 04/11/2020
The vulnerability identified as CVE-2018-19213 affects Netwide Assembler version 2.14rc16 and earlier, representing a critical memory management flaw that can result in denial of service conditions. This issue resides within the nasmlib/malloc.c component of the NASM codebase, specifically impacting the nasm_malloc function implementation. The vulnerability manifests as memory leaks that accumulate during the assembly process, potentially leading to system resource exhaustion and application instability.
The technical flaw stems from improper memory allocation and deallocation practices within the nasm_malloc function, which is responsible for managing dynamic memory requests during assembly operations. When NASM processes certain input files or assembly directives, the memory allocation routines fail to properly release allocated memory blocks, creating persistent memory leaks that grow with each successive assembly operation. This memory consumption pattern can be particularly problematic when processing large or complex assembly files, or when NASM is invoked repeatedly in automated environments.
From an operational perspective, this vulnerability presents significant risks to systems relying on NASM for assembly processing, particularly in automated build environments, continuous integration pipelines, or applications that invoke NASM as part of their workflow. The memory leaks can gradually consume available system resources until the system becomes unresponsive or crashes entirely, effectively creating a denial of service condition. Attackers could potentially exploit this vulnerability by submitting malicious assembly input files designed to trigger excessive memory allocation patterns, leading to resource exhaustion attacks against systems running NASM.
The impact of this vulnerability aligns with CWE-401, which categorizes memory leaks as a common weakness in software design and implementation. This classification emphasizes the fundamental nature of memory management flaws that can lead to resource exhaustion and system instability. From an adversarial perspective, this vulnerability maps to ATT&CK technique T1499.004, which covers network denial of service attacks through resource exhaustion, as the memory leaks can be leveraged to consume system resources and create denial of service conditions.
Mitigation strategies for CVE-2018-19213 should prioritize upgrading to NASM version 2.14 or later, where the memory leak issues have been addressed through improved memory management practices and proper deallocation of allocated resources. Organizations should also implement monitoring systems to detect unusual memory consumption patterns in systems running NASM, particularly in automated environments where the tool may be invoked repeatedly. Additionally, input validation and sanitization measures should be implemented to prevent malicious assembly files from being processed, and regular system resource monitoring should be maintained to detect potential exploitation attempts. The vulnerability serves as a reminder of the importance of proper memory management in software development and the critical need for thorough testing of memory allocation routines in tools that handle dynamic memory operations.