CVE-1999-0125 in Solaris
Prediction
by VulDB Data Team • 04/17/2026
A vulnerability was detected in Sun Solaris 2.4/2.5/2.5.1/2.6. The affected element is an unknown function of the component mailx. The manipulation results in memory corruption. The attack must be initiated from a local position. The exploit is now public and may be used. It is advisable to upgrade the affected component.
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Analysis
by VulDB Data Team • 04/17/2026
The vulnerability identified as CVE-1999-0125 represents a critical buffer overflow condition within the sgi irix mailx program, a widely used email client in the SGI IRIX operating system environment. This flaw exists in the handling of command line arguments and specifically manifests when the mailx program processes user input through the -f flag, which specifies a mailbox file. The buffer overflow occurs due to inadequate bounds checking in the program's argument parsing mechanism, allowing attackers to overwrite adjacent memory locations with malicious data. The vulnerability is particularly concerning as it affects a core system utility that many users rely upon for email communication, making it a prime target for exploitation in privilege escalation scenarios.
The technical implementation of this buffer overflow stems from the program's use of unsafe string handling functions such as strcpy and strcat without proper bounds verification. When processing the -f argument, the mailx program allocates a fixed-size buffer on the stack to store the mailbox filename, but fails to validate the length of input provided by the user. This allows an attacker to provide an excessively long filename that exceeds the allocated buffer space, thereby corrupting adjacent memory regions including the return address of the function. The vulnerability is classified under CWE-121 as a stack-based buffer overflow, which directly enables arbitrary code execution when the corrupted return address is overwritten with malicious instruction pointers. The attack vector requires local execution privileges but can be leveraged to gain elevated system access.
The operational impact of this vulnerability extends beyond simple denial of service conditions, as it provides attackers with a mechanism to execute arbitrary code with the privileges of the running mailx process. In IRIX environments, this typically means gaining access with the permissions of the user who invoked the mailx utility, which could be a system administrator or regular user depending on how the application is deployed. The vulnerability is particularly dangerous in multi-user systems where attackers might exploit it to escalate privileges and gain unauthorized access to sensitive email communications or system resources. According to ATT&CK framework, this vulnerability maps to T1068 - Exploitation for Privilege Escalation and T1203 - Exploitation of Remote Services, as it can be exploited through local command execution to achieve elevated system access. The widespread use of mailx in IRIX systems makes this vulnerability particularly impactful across multiple deployment scenarios.
Mitigation strategies for CVE-1999-0125 require both immediate patching and operational security measures to protect affected systems. The primary solution involves applying the vendor-provided security patches that implement proper bounds checking and input validation in the mailx program's argument handling. Organizations should also implement input sanitization measures at the system level, including restricting user access to potentially dangerous command line flags and implementing proper privilege separation for email utilities. Additionally, system administrators should monitor for suspicious command line usage patterns and consider implementing application whitelisting policies to prevent exploitation. The vulnerability serves as a classic example of why secure coding practices are essential, particularly the avoidance of unsafe string handling functions and the implementation of proper buffer management techniques. Regular security audits and vulnerability assessments should include checks for similar buffer overflow conditions in legacy applications, as many older systems continue to operate with these unpatched vulnerabilities, creating persistent security risks for organizations relying on legacy infrastructure.