SCA: security update for bundler (GHSA-fj7f-vq84-fh43)

high Tenable Self-Hosted Container Security Plugin ID 414553

Description

There are packages installed that are affected by a vulnerability referenced in the following CVE:

- `Bundler` is a package for managing application dependencies in Ruby. In `bundler` versions before 2.2.33,
when working with untrusted and apparently harmless `Gemfile`'s, it is not expected that they lead to
execution of external code, unless that's explicit in the ruby code inside the `Gemfile` itself. However,
if the `Gemfile` includes `gem` entries that use the `git` option with invalid, but seemingly harmless,
values with a leading dash, this can be false. To handle dependencies that come from a Git repository
instead of a registry, Bundler uses various commands, such as `git clone`. These commands are being
constructed using user input (e.g. the repository URL). When building the commands, Bundler versions
before 2.2.33 correctly avoid Command Injection vulnerabilities by passing an array of arguments instead
of a command string. However, there is the possibility that a user input starts with a dash (`-`) and is
therefore treated as an optional argument instead of a positional one. This can lead to Code Execution
because some of the commands have options that can be leveraged to run arbitrary executables. Since this
value comes from the `Gemfile` file, it can contain any character, including a leading dash. To exploit
this vulnerability, an attacker has to craft a directory containing a `Gemfile` file that declares a
dependency that is located in a Git repository. This dependency has to have a Git URL in the form of
`-u./payload`. This URL will be used to construct a Git clone command but will be interpreted as the
upload-pack argument. Then this directory needs to be shared with the victim, who then needs to run a
command that evaluates the Gemfile, such as `bundle lock`, inside. This vulnerability can lead to
Arbitrary Code Execution, which could potentially lead to the takeover of the system. However, the
exploitability is very low, because it requires a lot of user interaction. Bundler 2.2.33 has patched this
problem by inserting `--` as an argument before any positional arguments to those Git commands that were
affected by this issue. Regardless of whether users can upgrade or not, they should review any untrustred
`Gemfile`'s before running any `bundler` commands that may read them, since they can contain arbitrary
ruby code. (CVE-2021-43809)

Plugin Details

Severity: High

ID: 414553

Version: Revision 1.5

Type: Local

Family: SCA Checks

Published: 1/23/2025

Updated: 7/2/2026

Supported Sensors: Tenable Cloud Security, Tenable Self-Hosted Container Security

Risk Information

VPR

Risk Factor: Medium

Score: 4.9

Percentile: 57.15

Vendor

Vendor Severity: Medium

CVSS v2

Risk Factor: High

Base Score: 9.3

Temporal Score: 7.3

Vector: CVSS2#AV:N/AC:M/Au:N/C:C/I:C/A:C

CVSS Score Source: CVE-2021-43809

CVSS v3

Risk Factor: High

Base Score: 7.3

Temporal Score: 6.6

Vector: CVSS:3.0/AV:L/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H

Temporal Vector: CVSS:3.0/E:P/RL:O/RC:C

Vulnerability Information

Exploit Available: true

Exploit Ease: Exploits are available

Patch Publication Date: 12/8/2021

Vulnerability Publication Date: 12/8/2021

Reference Information

CVE: CVE-2021-43809

cwe: CWE-88

Detections

Analytics