Ceplin Command Identifier

Identifier / Programs / Linux and Unix

bundle

Dependency manager for the Ruby programming language. tldr-pages

GTFOBins inherit, shell 1 ATT&CK technique 5 documented commands

Opens the identifier with your command. It is read in your browser and sent nowhere.

How bundle is abused

documented by GTFOBins

inherit

help

inherit

console

shell T1059.004 Command and Scripting Interpreter: Unix Shell

exec

shell T1059.004 Command and Scripting Interpreter: Unix Shell

install

Each abuse is GTFOBins's category and the options and words it uses; the full write-up is on GTFOBins's page for bundle.

5 documented commands

from GTFOBins, each read by the identifier

inherit unprivileged, with sudo

bundle help
Identify

inherit unprivileged, with sudo

touch Gemfile
bundle console
Identify

shell unprivileged, with sudo

BUNDLE_GEMFILE=x bundle exec /bin/sh
Identify

shell unprivileged, with sudo

touch Gemfile
bundle exec /bin/sh
Identify

shell unprivileged, with sudo

This might run the shell twice, one after the other.

echo 'system("/bin/sh")' >Gemfile
bundle install
Identify

None of the 5 commands the identifier reads trips a Sigma process-creation rule. These commands are, with GTFOBins’ notes, from GTFOBins, at commit acd524623f9c of 2026-05-27, under the GPL-3.0, with no warranty. Changed: Markdown is shown formatted. The source is in lolbas-gtfobins-commands.json.gz, and the full entry is on GTFOBins’s page for bundle. The identifier reads the line of each that runs bundle.

What detects it

Sigma process creation rules
T1059.004Command and Scripting Interpreter: Unix Shell

Everyday use

from tldr-pages, CC BY 4.0

Install all gems defined in the Gemfile expected in the working directory

bundle installIdentify

Matches GTFOBins abuse: shell

Execute a command in the context of the current bundle

bundle exec command argumentsIdentify

Update all gems by the rules defined in the Gemfile and regenerate Gemfile.lock

bundle update --allIdentify

Of the 3 examples the identifier reads, 1 matches GTFOBins abuse or trips a Sigma process-creation rule.