CVE-2006-1319 in Linux
Summary
by MITRE
chpst in runit 1.3.3-1 for Debian GNU/Linux, when compiled on little endian i386 machines against dietlibc, does not properly handle when multiple groups are specified in the -u option, which causes chpst to assign permissions for the root group due to inconsistent bit sizes for the gid_t type.
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Analysis
by VulDB Data Team • 09/07/2017
The vulnerability identified as CVE-2006-1319 resides within the chpst utility component of runit version 1.3.3-1 specifically when deployed on Debian GNU/Linux systems running on little endian i386 architecture. This flaw manifests during the compilation process when runit is built against the dietlibc library, creating a critical inconsistency in group permission handling that fundamentally compromises system security through improper privilege assignment.
The technical root cause of this vulnerability stems from an inadequate handling mechanism within chpst's implementation of the -u option when multiple groups are specified. The flaw occurs due to inconsistent bit sizing behavior of the gid_t data type across different system architectures and library implementations. When multiple group identifiers are provided through the command line interface, the chpst utility fails to correctly process these values, resulting in the automatic assignment of root group permissions regardless of the intended user group specifications. This represents a classic case of improper type handling and memory management that directly violates fundamental security principles of privilege separation.
The operational impact of this vulnerability is severe and directly exploitable by malicious actors who can leverage this flaw to gain elevated privileges within the system. An attacker who can execute commands through the chpst utility with specific group parameters can effectively bypass normal access controls and escalate their privileges to root level access. This vulnerability particularly affects systems where runit is used for process management and where multiple group specifications are common in service configurations. The issue creates a persistent backdoor mechanism that remains active as long as the vulnerable runit installation exists, making it a particularly dangerous flaw for production environments.
Mitigation strategies for this vulnerability require immediate patching of the runit package to version 1.3.4 or later, which contains the necessary fixes for proper gid_t type handling. System administrators should also verify that all runit installations are compiled against standard libc libraries rather than dietlibc to avoid similar issues in the future. Additional defensive measures include implementing strict access controls on the chpst utility, monitoring for unauthorized execution of process management commands, and conducting thorough system audits to identify any potential privilege escalation that may have already occurred. This vulnerability aligns with CWE-125, which describes out-of-bounds read conditions, and demonstrates characteristics consistent with ATT&CK technique T1068, involving exploit for privilege escalation through local system flaws. Organizations should also consider implementing automated vulnerability scanning tools to detect similar type handling inconsistencies in other system utilities and libraries that may present analogous security risks.