Numeric Identifier Truncation in su-exec Privilege Escalation

CVE-2026-82457 represents a critical privilege escalation vulnerability in su-exec version 0.3 stemming from improper input validation of numeric user and group identifiers. The vulnerability exploits a type conversion flaw where large numeric values parsed via strtol are truncated when assigned to uid_t and gid_t data types, allowing attackers to craft malicious identifiers that wrap around to zero—root's effective UID. This affects any system running the vulnerable su-exec version where unprivileged users can influence the numeric identifiers passed to the utility, potentially enabling local privilege escalation to execute arbitrary commands with root privileges. The impact is particularly severe in containerized environments, multi-tenant systems, and privileged access management contexts where su-exec is relied upon to enforce privilege separation.

While this CVE does not map to specific MITRE ATT&CK techniques, Casky's 754 mapped security skills enable detection of the underlying abuse patterns through extended reasoning across privilege escalation, code injection, and access control techniques. Practitioners using Casky would identify suspicious patterns such as: abnormally large numeric values in user/group ID arguments to su-exec, unexpected privilege elevation to root context from unprivileged processes, and behavioral anomalies where processes suddenly execute with elevated capabilities. The platform's Claude AI-powered analysis would correlate these indicators with CWE-681 (Incorrect Conversion Between Numeric Types) patterns, flagging processes that attempt to exploit type boundary conditions. Security teams would see findings highlighting suspicious su-exec invocations with out-of-range numeric parameters, unusual privilege transitions, and process lineage anomalies—enabling rapid detection before attackers gain persistent root access.