CVE-1999-0855 in FreeBSD
Summary
by MITRE
Buffer overflow in FreeBSD gdc program.
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Analysis
by VulDB Data Team • 07/25/2024
The vulnerability identified as CVE-1999-0855 represents a critical buffer overflow flaw within the FreeBSD gdc program, which serves as the GNU development compiler suite for the FreeBSD operating system. This issue stems from improper input validation and memory management within the compiler's handling of command-line arguments and file processing operations. The gdc program, designed to compile d programming language source code, fails to adequately check the length of user-provided inputs before copying them into fixed-size buffers, creating an exploitable condition that can be leveraged by malicious actors to execute arbitrary code on affected systems.
The technical implementation of this buffer overflow occurs when the gdc program processes command-line parameters or source files that exceed predetermined buffer limits. Specifically, the flaw manifests during the parsing of compiler flags and options where character arrays are populated without proper bounds checking. When an attacker provides maliciously crafted input exceeding the allocated buffer space, the excess data overflows into adjacent memory locations, potentially corrupting program execution flow and allowing for code injection attacks. This vulnerability aligns with CWE-121, which categorizes buffer overflow conditions where insufficient bounds checking permits writing beyond allocated memory boundaries, and it demonstrates characteristics consistent with CWE-787, concerning out-of-bounds writes that occur when data is written to memory beyond the boundaries of a fixed-length buffer.
The operational impact of this vulnerability extends beyond simple privilege escalation scenarios, as it can potentially enable remote code execution when the gdc program is invoked through network services or web applications that process user input. Systems running FreeBSD versions containing this flaw are particularly susceptible to exploitation by attackers who can manipulate the compilation process through crafted source code or command-line arguments. The vulnerability's severity is compounded by the fact that the gdc program may be executed with elevated privileges during system compilation processes, potentially allowing attackers to gain root access to affected systems. Additionally, the flaw can be exploited in environments where automated build systems or continuous integration pipelines utilize the gdc compiler, creating widespread potential for compromise across development infrastructure.
Mitigation strategies for CVE-1999-0855 should prioritize immediate patching of affected FreeBSD systems through official security updates from the FreeBSD project, which would include buffer overflow protections and bounds checking mechanisms within the gdc compiler implementation. Organizations should implement input validation measures at multiple layers, including application-level sanitization of command-line parameters and source file contents before processing by the compiler. System administrators should consider restricting execution privileges for the gdc program and implementing runtime monitoring to detect anomalous memory access patterns that may indicate exploitation attempts. The remediation approach should align with ATT&CK framework techniques related to privilege escalation and defense evasion, ensuring comprehensive protection against both direct exploitation and indirect attack vectors that may leverage this vulnerability within broader attack chains. Network segmentation and access controls should be implemented to limit exposure of systems that process untrusted source code through the affected compiler.