Summary
Arbitrary File Overwrite in Eclipse JGit
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.
Impact
CVE-2023-4759 has a CVSS score of 8.8 (High). The vector is network-reachable, low privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (6.6.1.202309021850-r, 5.13.3.202401111512-r); upgrading removes the vulnerable code path.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
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org.eclipse.jgit:org.eclipse.jgit to 6.6.1.202309021850-r or later; org.eclipse.jgit:org.eclipse.jgit to 5.13.3.202401111512-r or later
Kodem Kai can prioritize this vulnerability in your dependency tree and generate a fix recommendation.
Frequently Asked Questions
- What is CVE-2023-4759? CVE-2023-4759 is a high-severity security vulnerability in org.eclipse.jgit:org.eclipse.jgit (maven), affecting versions >= 6.0.0.202111291000-r, <= 6.6.0.202305301015-r. It is fixed in 6.6.1.202309021850-r, 5.13.3.202401111512-r.
- How severe is CVE-2023-4759? CVE-2023-4759 has a CVSS score of 8.8 (High). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
- Which versions of org.eclipse.jgit:org.eclipse.jgit are affected by CVE-2023-4759? org.eclipse.jgit:org.eclipse.jgit (maven) versions >= 6.0.0.202111291000-r, <= 6.6.0.202305301015-r is affected.
- Is there a fix for CVE-2023-4759? Yes. CVE-2023-4759 is fixed in 6.6.1.202309021850-r, 5.13.3.202401111512-r. Upgrade to this version or later.
- Is CVE-2023-4759 exploitable, and should I be worried? Whether CVE-2023-4759 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2023-4759 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix CVE-2023-4759?
- Upgrade
org.eclipse.jgit:org.eclipse.jgitto 6.6.1.202309021850-r or later - Upgrade
org.eclipse.jgit:org.eclipse.jgitto 5.13.3.202401111512-r or later
- Upgrade