CVE-2015-8968: Git fastclone Git-fastclone Permits Arbitrary Shell Command Vulnerability

HIGH
Advisory Identifier: GHSA-8gg6-3r63-25m8
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CVSS 8.8
CWE-77
Published
Advisory Summary

CVE-2015-8968 is a HIGH (CVSS 8.8) git-fastclone permits arbitrary shell command vulnerability (CWE-77: Improper Neutralization of Special Elements used in a Command ('Command Injection')) affecting Git fastclone libraries in the RubyGems ecosystem. The issue involves git-fastclone permits arbitrary shell command execution from .gitmodules. Remediation is available by upgrading affected packages to version 1.0.1.

CVE-2015-8968 at a Glance

CVE Identifier CVE-2015-8968
GHSA Identifier GHSA-8gg6-3r63-25m8
Severity HIGH
CVSS v3.1 Base Score 8.8
CWE Classification CWE-77: Improper Neutralization of Special Elements used in a Command ('Command Injection')
Affected Product Git fastclone
Package Ecosystem RubyGems
Published Date
Last Updated

Security Impact

CVSS: 8.8

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H).

Attack Vector Network (AV:N)
Attack Complexity Low (AC:L)
Privileges Required None (PR:N)
User Interaction Required (UI:R)
Scope Unchanged (S:U)
Confidentiality High (C:H)
Integrity High (I:H)
Availability High (A:H)

How to Fix CVE-2015-8968

To remediate this vulnerability, upgrade all affected Git fastclone dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

git-fastclone fixed: 1.0.1 
Upgrade git-fastclone to 1.0.1
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

inspect dependencies for git-fastclone

How to Check if You Are Affected

To determine whether your application is affected by CVE-2015-8968, inspect your project dependencies for Git fastclone:

inspect dependencies for git-fastclone

Analyze the terminal output to locate any version of Git fastclone in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 1.0.1), your application is affected.

Note: Verify declared build manifests and deployed runtime container environments.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-77: Improper Neutralization of Special Elements used in a Command ('Command Injection'), where the product constructs all or part of a command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended command when it is sent to a downstream component. In Git fastclone, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

git-fastclone before 1.0.1 permits arbitrary shell command execution from .gitmodules. If an attacker can instruct a user to run a recursive clone from a repository they control, they can get a client to run an arbitrary shell command. Alternately, if an attacker can MITM an unencrypted git clone, they could exploit this. The ext command will be run if the repository is recursively cloned or if submodules are updated. This attack works when cloning both local and remote repositories.

CVE-2015-8968 Affected Git fastclone Versions

1 component(s)
Fixed Versions:
1.0.1
Product / Package Ecosystem Affected Versions Fixed Version
git-fastclone
gem/git-fastclone
RubyGems
< 1.0.1
1.0.1

References

NVD — CVE-2015-8968 NVD
https://nvd.nist.gov/vuln/detail/CVE-2015-8968
Git fastclone Source Repository REPOSITORY
https://github.com/square/git-fastclone/pull/2
hackerone.com/reports/104465 WEB
https://hackerone.com/reports/104465
Git fastclone Source Repository REPOSITORY
https://github.com/rubysec/ruby-advisory-db/blob/master/gems/git-fastclone/CVE-2015-8968.yml
Git fastclone Source Repository REPOSITORY
https://github.com/square/git-fastclone
Git fastclone Security Information SECURITY
https://web.archive.org/web/20200227213019/http://www.securityfocus.com/bid/81433

Frequently Asked Questions

What is CVE-2015-8968?
CVE-2015-8968 is a security vulnerability in Git fastclone involving git-fastclone permits arbitrary shell command execution from .gitmodules under CWE-77: Improper Neutralization of Special Elements used in a Command ('Command Injection').
Which Git fastclone versions are affected?
Affected versions include releases prior to 1.0.1 across affected packages: git-fastclone.
What version fixes CVE-2015-8968?
Upgrading to 1.0.1 (or the latest patched release for your respective branch) resolves the vulnerability.
Is git-fastclone affected?
Yes, git-fastclone is affected in releases prior to 1.0.1. Upgrade your dependency to 1.0.1 or later.
What is the CVSS score of CVE-2015-8968?
CVE-2015-8968 has a CVSS v3.1 base score of 8.8 (HIGH) with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H.
What CWE is associated with CVE-2015-8968?
CVE-2015-8968 is classified under CWE-77: Improper Neutralization of Special Elements used in a Command ('Command Injection') (The product constructs all or part of a command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended command when it is sent to a downstream component.).
How can I check RubyGems dependencies for CVE-2015-8968?
Run the dependency tree command: 'inspect dependencies for git-fastclone'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-8gg6-3r63-25m8",
  "modified" : "2023-08-29T12:09:29Z",
  "published" : "2018-08-15T20:03:37Z",
  "aliases" : [ "CVE-2015-8968" ],
  "summary" : "git-fastclone permits arbitrary shell command execution from .gitmodules",
  "details" : "git-fastclone before 1.0.1 permits arbitrary shell command execution from .gitmodules. If an attacker can instruct a user to run a recursive clone from a repository they control, they can get a client to run an arbitrary shell command. Alternately, if an attacker can MITM an unencrypted git clone, they could exploit this. The ext command will be run if the repository is recursively cloned or if submodules are updated. This attack works when cloning both local and remote repositories.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "RubyGems",
      "name" : "git-fastclone"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "1.0.1"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2015-8968"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/square/git-fastclone/pull/2"
  }, {
    "type" : "WEB",
    "url" : "https://hackerone.com/reports/104465"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/rubysec/ruby-advisory-db/blob/master/gems/git-fastclone/CVE-2015-8968.yml"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/square/git-fastclone"
  }, {
    "type" : "WEB",
    "url" : "https://web.archive.org/web/20200227213019/http://www.securityfocus.com/bid/81433"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-77" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2020-06-16T21:25:37Z",
    "nvd_published_at" : null
  }
}