# What is CVE-2023-4759? > CVE-2023-4759 is a high-severity flaw (CVSS 8.8) in Jgit from Eclipse, published on 12 September 2023. It is not on the list of flaws known to be exploited today. The latest forecast puts its chance of use in the next 30 days at 2.2%. If you run an affected version, plan in the vendor’s fix. Canonical page: https://www.precursorintelligence.com/what-is/cve-2023-4759 ## At a glance - **Verdict:** Plan it in. No sign of exploitation and a low forecast. Patch it in your normal update cycle. - **Precursor Intelligence risk score:** 50 out of 100 (Medium); action: Plan remediation. Kept up to date as the evidence changes. - **Severity:** High (CVSS 8.8 out of 10) - **Known to be exploited:** No, not on the list of flaws known to be exploited today - **Chance of use in the next 30 days:** 2.2% (latest exploit-likelihood forecast) - **Published:** 12 September 2023 - **Record last updated:** 7 August 2024 - **Main product:** Jgit from Eclipse - **Affected products:** 3 ## What is CVE-2023-4759? In plain terms It can be attacked from anywhere on the internet with an ordinary user account, and nobody has to click anything. If it works, the attacker can read data, change data and take it offline. ### The official description 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. ### What kind of flaw is it? - CWE-59: Improper Link Resolution Before File Access ('Link Following') - CWE-178: Improper Handling of Case Sensitivity ### How an attack on it works - Where an attacker can be: Anywhere on the internet - How hard it is to pull off: Easy: no special conditions - Login needed first: An ordinary user account - Does someone have to click: No, nobody has to do anything - What an attacker gets: Can read data, change data and take it offline Severity vector: `CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H` ## Is CVE-2023-4759 being exploited? Not that we know of It is not on the list of flaws known to be exploited today. The latest forecast puts the chance of it being used in the next 30 days at 2.2%. That can change at any time, which is why we keep watching. Exploit likelihood over the last 7 days: 2.2%, 2.2%, 2.2%, 2.2%, 2.2%, 2.2%, 2.2%. ### Timeline - 12 September 2023: Published - 7 August 2024: Record last updated ### How Precursor Intelligence ranks it CVE-2023-4759 scores **50 out of 100 (Medium)**, with the action "Plan remediation". Every published flaw gets a risk score from 0 to 100, kept up to date as the evidence changes. Four things go into the score, from the one that counts most to the ones that count less: - Evidence it is being exploited: biggest factor - How severe it is: strong factor - How widely exposed it is: smaller factor - Threat activity around it: smaller factor 85 and above is Critical. Anything confirmed as exploited is always marked for an emergency patch, whatever its score. When this flaw matches software you track, it lands in your list with its score and the reasons behind it. ## Who is affected by CVE-2023-4759? The published record lists 3 products. Versions are as published: "before 5.13.3.202401111512-r" means every version up to, but not including, 5.13.3.202401111512-r. - [Jgit](https://www.precursorintelligence.com/product/eclipse/jgit) by [Eclipse](https://www.precursorintelligence.com/vendors/eclipse) (Application): before 5.13.3.202401111512-r, 6.6.0 to before 6.6.0.202305301015, 6.7.0 to before 6.7.0.202309050840 - [macOS](https://www.precursorintelligence.com/product/apple/macos) by [Apple](https://www.precursorintelligence.com/vendors/apple) (Operating system): version not specified - [Windows](https://www.precursorintelligence.com/product/microsoft/windows) by [Microsoft](https://www.precursorintelligence.com/vendors/microsoft) (Operating system): version not specified ## How do I fix CVE-2023-4759? 1. **Check whether you run it.** Compare your versions with the affected products above. Not sure what you run? Precursor Intelligence can work it out from your public website, or you can pick it from a list. 2. **Apply the vendor’s fix.** Install the update named in the vendor’s advisory. We’ve put the advisories and patch notes first in the list. 3. **If you can’t patch today.** Follow any mitigation the vendor publishes, and limit who can reach the affected system from the internet until the update is in. 4. **Keep an eye on it.** Track the product and we tell you as soon as we spot this flaw on the list of exploited flaws, or a jump in its exploit likelihood. ### References - [git.eclipse.org](https://git.eclipse.org/c/jgit/jgit.git/commit/?id=9072103f3b3cf64dd12ad2949836ab98f62dabf1) (Patch, Vendor advisory) - [gitlab.eclipse.org](https://gitlab.eclipse.org/security/vulnerability-reports/-/issues/11) (Issue tracking, Vendor advisory) - [projects.eclipse.org](https://projects.eclipse.org/projects/technology.jgit/releases/6.6.1) (Release notes, Vendor advisory) ## Questions ### What is CVE-2023-4759? CVE-2023-4759 is a high-severity flaw in Jgit from Eclipse, published on 12 September 2023. It can be attacked from anywhere on the internet with an ordinary user account, and nobody has to click anything. If it works, the attacker can read data, change data and take it offline. ### How serious is CVE-2023-4759? It scores 8.8 out of 10 on the CVSS severity scale, which is high. Our risk score for CVE-2023-4759 is 50 out of 100, which is Medium. Its action is "Plan remediation". No sign of exploitation and a low forecast. Patch it in your normal update cycle. ### Is CVE-2023-4759 being exploited? It is not on the list of flaws known to be exploited today. The latest forecast puts the chance of it being used in the next 30 days at 2.2%. That can change at any time, which is why we keep watching. ### Which versions does CVE-2023-4759 affect? For Jgit from Eclipse: before 5.13.3.202401111512-r, 6.6.0 to before 6.6.0.202305301015, 6.7.0 to before 6.7.0.202309050840. The record lists 3 products in all, each with its versions, under "Who is affected" on this page. ### How do I fix CVE-2023-4759? Install the update the vendor names in its advisory, linked first under "How do I fix" on this page. If you can't patch today, follow the vendor's mitigation and limit who can reach the affected system from the internet. ## Does CVE-2023-4759 affect you? Precursor Intelligence keeps checking for you: - **Tell us what you run.** Pick your software from a list, or let us work it out from your website. - **We match it to every flaw.** Over 400,000 published flaws, checked against your list. - **Ranked by real-world risk.** Every flaw gets a 0 to 100 risk score, kept up to date, led by evidence criminals are using it. - **Told as soon as we know.** An alert by email, in the app or by webhook to your own tools. Start free (no card, nothing to install): https://www.precursorintelligence.com/register Book a demo: https://www.precursorintelligence.com/contact