CVE-2018-20990
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedAn issue was discovered in the tar crate before 0.4.16 for Rust. Arbitrary file overwrite can occur via a symlink or hardlink in a TAR archive.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · high confidenceThe tar crate before 0.4.16 for Rust does not properly sanitize symlinks and hardlinks during TAR archive extraction. An attacker can craft a malicious TAR archive containing symlinks or hardlinks that point to files outside the intended extraction directory, enabling arbitrary file overwrite on the victim's system.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data< 0.4.16CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- Low
- Privileges
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- High
- Availability
- None
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
-
Locate the tar crate dependencySearch your project's Cargo.toml file for the 'tar' crate under the [dependencies] sectionAffected if The tar crate is listed as a dependency and its version is below 0.4.16 or not explicitly specified with a fixed version
-
Check the resolved crate versionInspect your Cargo.lock file for the [[package]] entry with name "tar" and note the version fieldAffected if The version field shows a version lower than 0.4.16
-
Identify TAR extraction code pathsSearch your source code for invocations of tar::Archive or Archive::new followed by extraction methods such as unpack, extract, or entries()Affected if Code exists that creates Archive instances and extracts from TAR files
-
Determine trust boundary of archivesReview the source code to identify the origin of TAR archives being extracted - check if they come from user input, network sources, or untrusted locationsAffected if Extraction is performed on archives from untrusted or attacker-controlled sources
You are affected if your project depends on the tar crate with a version below 0.4.16 AND your code extracts TAR archives from untrusted sources, allowing potential arbitrary file overwrite via malicious symlinks or hardlinks.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
From vendor data0.4.16
Upgrade the tar crate to version 0.4.16 or later. Additionally, validate that extracted symlinks and hardlinks resolve within the intended destination directory before writing any files.
- Consultation2.0 h
- Implementation1.0 h
- Testing4.0 h
- Review / QA1.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $2,176.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2018-20990 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2018-20990 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.
A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.
- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
- No weaponised exploit code, or anything meant to cause harm
- No spam, self-promotion, credentials, or personal data