CVE-1999-0767 in Solaris
Summary
by MITRE
Buffer overflow in Solaris libc, ufsrestore, and rcp via LC_MESSAGES environmental variable.
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Analysis
by VulDB Data Team • 06/05/2024
The vulnerability identified as CVE-1999-0767 represents a critical buffer overflow flaw affecting multiple components within the Solaris operating system's libc library and associated utilities including ufsrestore and rcp. This issue stems from improper handling of the LC_MESSAGES environmental variable which is used to specify message catalog locales for internationalization purposes. The flaw manifests when these system components process user-supplied input through the LC_MESSAGES environment variable without adequate bounds checking, allowing attackers to overwrite adjacent memory locations and potentially execute arbitrary code.
The technical implementation of this vulnerability resides in the string handling functions within the libc library that are responsible for processing locale-specific messages. When the ufsrestore utility or rcp command encounters a specially crafted LC_MESSAGES value, the system's internationalization framework fails to validate the length of the input string before copying it into fixed-size buffers. This classic buffer overflow condition creates an opportunity for attackers to overwrite return addresses, function pointers, or other critical program state information within the stack. The vulnerability affects Solaris systems running on various architectures and is particularly concerning because it can be exploited through network-based attacks when these utilities are invoked with network services such as rcp or rsh.
The operational impact of CVE-1999-0767 extends beyond simple privilege escalation to encompass potential system compromise and unauthorized access to sensitive data. Attackers can leverage this vulnerability to execute malicious code with the privileges of the affected process, which typically runs with elevated permissions when invoked through network services. The attack vector is particularly dangerous because it can be triggered remotely without requiring direct system access, making it an attractive target for attackers seeking to establish persistent access to Solaris systems. The vulnerability also demonstrates the broader challenge of internationalization features in system software, where localization mechanisms can introduce security weaknesses if not properly validated against buffer size constraints. This flaw aligns with CWE-121, which describes buffer overflow conditions in stack-based buffers, and can be categorized under the ATT&CK technique T1059 for command and scripting interpreter, as successful exploitation would enable attackers to execute arbitrary commands on compromised systems.
Mitigation strategies for this vulnerability require immediate patching of affected Solaris systems through official security updates provided by Sun Microsystems. System administrators should also implement runtime protections such as address space layout randomization and stack canaries to make exploitation more difficult. Additionally, the use of privilege separation techniques and input validation should be enforced for all internationalization features within system utilities. The vulnerability highlights the importance of maintaining secure coding practices in system libraries and demonstrates how seemingly benign features like locale support can introduce critical security weaknesses when not properly implemented with appropriate bounds checking and input validation measures. Organizations should conduct comprehensive vulnerability assessments to identify other system components that may be susceptible to similar buffer overflow conditions, particularly those involving internationalization and localization features.