MITRE ATT&CK technique

T1166

Setuid and Setgid

About this technique

When the setuid or setgid bits are set on Linux or macOS for an application, this means that the application will run with the privileges of the owning user or group respectively (Citation: setuid man page). Normally an application is run in the current user’s context, regardless of which user or group owns the application.

Read the full ATT&CK description

There are instances where programs need to be executed in an elevated context to function properly, but the user running them doesn’t need the elevated privileges. Instead of creating an entry in the sudoers file, which must be done by root, any user can specify the setuid or setgid flag to be set for their own applications. These bits are indicated with an "s" instead of an "x" when viewing a file's attributes via <code>ls -l</code>.

The <code>chmod</code> program can set these bits with via bitmasking, <code>chmod 4777 [file]</code> or via shorthand naming, <code>chmod u+s [file]</code>.

An adversary can take advantage of this to either do a shell escape or exploit a vulnerability in an application with the setsuid or setgid bits to get code running in a different user’s context. Additionally, adversaries can use this mechanism on their own malware to make sure they're able to execute in elevated contexts in the future (Citation: OSX Keydnap malware).

TA0003TA0004
Curated mapping

Curated incident relationships

These associations come from maintained incident records. The recorded confidence is shown when the source record provides it.

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No curated incident mappings yet.
Heuristic association

Daily items linked through predicted CVEs

A Daily item appears here when it mentions a CVE whose triage artifact predicts this technique. This is not a verified ATT&CK mapping.

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No heuristic Daily associations yet.
Heuristic association

Predicted CVE associations

These backfilled or model-produced candidates come from the current triage artifact. They are informational, not official MITRE mappings.

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No predicted associations yet for this technique.
T1166 · Setuid and Setgid · Baitaphish