CVE-2018-10316 in Netwide Assembler
Summary
by MITRE
Netwide Assembler (NASM) 2.14rc0 has an endless while loop in the assemble_file function of asm/nasm.c because of a globallineno integer overflow.
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Analysis
by VulDB Data Team • 01/30/2020
The vulnerability identified as CVE-2018-10316 affects the Netwide Assembler (NASM) version 2.14rc0, a widely used assembler for generating machine code from assembly language source files. This critical flaw manifests as an infinite while loop within the assemble_file function located in the asm/nasm.c source file, creating a significant denial of service condition that can be exploited by malicious actors. The vulnerability stems from a fundamental integer overflow issue involving the global lineno variable, which tracks line numbers during assembly processing.
The technical implementation of this vulnerability occurs when the lineno global variable exceeds its maximum representable value for the integer type, causing the while loop condition to never terminate. This integer overflow represents a classic software defect pattern that falls under CWE-190, specifically Integer Overflow or Wraparound, where an integer value exceeds its maximum limit and wraps around to a much smaller value. The assembly process becomes stuck in an infinite loop, consuming system resources indefinitely until manually terminated, effectively creating a denial of service condition for any application or system attempting to process assembly files through this vulnerable version of NASM.
The operational impact of CVE-2018-10316 extends beyond simple service disruption, as it can be leveraged by attackers to consume system resources and potentially cause system instability. When an attacker provides a malicious assembly file that triggers this condition, the assembler enters an endless loop that can exhaust CPU cycles and memory resources, making the system unresponsive to legitimate assembly processing requests. This vulnerability is particularly concerning in environments where NASM is used as part of automated build processes, continuous integration pipelines, or as a component in larger software development toolchains, where such a denial of service condition could severely impact productivity and system availability.
Mitigation strategies for this vulnerability involve immediate upgrading to a patched version of NASM where the integer overflow condition has been properly addressed through bounds checking and appropriate integer handling mechanisms. Organizations should also implement input validation measures to prevent potentially malicious assembly files from being processed by NASM, including file format verification and size limitations. From an operational security perspective, this vulnerability aligns with ATT&CK technique T1499.004, which covers Network Denial of Service, as the infinite loop creates a resource exhaustion condition that impacts system availability. Additionally, implementing proper code review processes that include static analysis tools capable of detecting integer overflow conditions would help prevent similar issues in other software components that may be susceptible to the same class of vulnerabilities.