# CVE-2020-26312: GHSL-2020-254: Arbitrary file read and/or write in dotmesh > Attackers can read or write arbitrary files outside the target directory via malicious tarballs exploiting symbolic link handling in dotmesh. - **Severity:** High 8.1 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N`) - **Exploited in the wild:** Not known - **Login needed:** Any signed-in user - **Attackable:** Over the internet - **Victim action needed:** Not needed - **Fix available:** No - **Published:** 14 May 2024 - **Updated:** 4 Aug 2024 - **Also known as:** GHSA-hf54-fq2m-p9v6, GO-2024-2849 ## What is CVE-2020-26312? CVE-2020-26312 is a high-severity path traversal vulnerability in dotmesh-io dotmesh, published on 14 May 2024. Any signed-in user can exploit it over the network, with no action from the victim. ### Official description Dotmesh is a git-like command-line interface for capturing, organizing and sharing application states. In versions 0.8.1 and prior, the unsafe handling of symbolic links in an unpacking routine may enable attackers to read and/or write to arbitrary locations outside the designated target folder. The routine `untarFile` attempts to guard against creating symbolic links that point outside the directory a tar archive is extracted to. However, a malicious tarball first linking `subdir/parent` to `..` (allowed, because `subdir/..` falls within the archive root) and then linking `subdir/parent/escapes` to `..` results in a symbolic link pointing to the tarball’s parent directory, contrary to the routine’s goals. This issue may lead to arbitrary file write (with same permissions as the program running the unpack operation) if the attacker can control the archive file. Additionally, if the attacker has read access to the unpacked files, they may be able to read arbitrary system files the parent process has permissions to read. As of time of publication, no patch for this issue is available. Weakness: CWE-787 (Out-of-bounds Write), CWE-125 (Out-of-bounds Read) ## Which versions are affected by CVE-2020-26312? 3 open source packages ship an affected version, including github.com/dotmesh-io/dotmesh. | Package | Ecosystem | Affected | Fixed in | | --- | --- | --- | --- | | `github.com/dotmesh-io/dotmesh` | Go | All versions | None | | `github.com/dotmesh-io/dotmesh` | Go | All versions to 0.8.1 | None | | `github.com/dotmesh-io/dotmesh` | Go | All versions to 0.8.1 | None | ## How do I fix CVE-2020-26312? No fix has been published for CVE-2020-26312 yet. Limit exposure of the affected software until one is available. ## Is CVE-2020-26312 being exploited? It is not confirmed as exploited in the wild, but public exploit code for CVE-2020-26312 exists. ## Fix prompt for AI coding agents ```text Check this codebase for CVE-2020-26312 and fix it if it is affected. What it is: CVE-2020-26312 is a high-severity path traversal vulnerability in dotmesh-io dotmesh, published on 14 May 2024. Any signed-in user can exploit it over the network, with no action from the victim. Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2020-26312 exists. Affected packages and fixed versions: - github.com/dotmesh-io/dotmesh (Go): affected all versions; no fix listed - github.com/dotmesh-io/dotmesh (Go): affected all versions up to 0.8.1; no fix listed - github.com/dotmesh-io/dotmesh (Go): affected all versions up to 0.8.1; no fix listed Task: 1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies. 2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it. 3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead. 4. Run the tests and summarise what changed and why. 5. If nothing in the project is affected, say so and change nothing. Reference: https://insights.sbomify.com/CVE-2020-26312/ (Markdown: https://insights.sbomify.com/CVE-2020-26312/index.md) ``` ## Sources - CVE record: https://www.cve.org/CVERecord?id=CVE-2020-26312 - NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-26312 - OSV: https://osv.dev/vulnerability/CVE-2020-26312 --- From sbomify Insights: https://insights.sbomify.com/CVE-2020-26312/ Summaries are generated and may contain mistakes; the official description above is the record.