CVE-2023-4759 Improper handling of case insensitive filesystems in Eclipse JGit allows arbitrary file write

2023-09-1209:12:10

CWE-59

CWE-178

eclipse

www.cve.org

eclipse jgit

arbitrary file overwrite

cve-2023-4759

case insensitive filesystems

remote code execution

symbolic links

git configuration

8.8 High

CVSS3

Attack Vector

NETWORK

Attack Complexity

LOW

Privileges Required

NONE

User Interaction

REQUIRED

Scope

UNCHANGED

Confidentiality Impact

HIGH

Integrity Impact

HIGH

Availability Impact

HIGH

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

9 High

AI Score

Confidence

High

0.001 Low

EPSS

Percentile

48.0%

JSON

Arbitrary File Overwrite in Eclipse JGit <= 6.6.0

In Eclipse JGit, all versions <= 6.6.0.202305301015-r, a symbolic link present in a specially crafted git repository can be used to write a file to locations outside the working tree when this repository is cloned with JGit to a case-insensitive filesystem, or when a checkout from a clone of such a repository is performed on a case-insensitive filesystem.

This can happen on checkout (DirCacheCheckout), merge (ResolveMerger via its WorkingTreeUpdater), pull (PullCommand using merge), and when applying a patch (PatchApplier). This can be exploited for remote code execution (RCE), for instance if the file written outside the working tree is a git filter that gets executed on a subsequent git command.

The issue occurs only on case-insensitive filesystems, like the default filesystems on Windows and macOS. The user performing the clone or checkout must have the rights to create symbolic links for the problem to occur, and symbolic links must be enabled in the git configuration.

Setting git configuration option core.symlinks = false before checking out avoids the problem.

The issue was fixed in Eclipse JGit version 6.6.1.202309021850-r and 6.7.0.202309050840-r, available via Maven Central https://repo1.maven.org/maven2/org/eclipse/jgit/ and repo.eclipse.org https://repo.eclipse.org/content/repositories/jgit-releases/ . A backport is available in 5.13.3 starting from 5.13.3.202401111512-r.

The JGit maintainers would like to thank RyotaK for finding and reporting this issue.

CNA Affected

[
  {
    "collectionURL": "https://git.eclipse.org/c/jgit/jgit.git/",
    "defaultStatus": "unaffected",
    "product": "Eclipse JGit",
    "vendor": "Eclipse Foundation",
    "versions": [
      {
        "lessThanOrEqual": "6.6.0.202305301015-r",
        "status": "affected",
        "version": "0.0.0",
        "versionType": "semver"
      },
      {
        "status": "unaffected",
        "version": "  5.13.3.202401111512-r"
      }
    ]
  }
]