CVE-2021-32841
Path Traversal in SharpZipLib
No known exploitation. EPSS puts it in the 65th percentile. Fixed versions are out.
What to do
Find your product and version, then upgrade to the build on the right.
- Icsharpcode SharpziplibAffected: ≥ 1.3.3, < 1.3.3Upgrade to: 1.3.3Affected: ≥ 1.3.0, < 1.3.0*Upgrade to: 1.3.0*Stated by: CVE record
- NuGet SharpZipLibAffected: ≥ 1.3.0, < 1.3.3Upgrade to: 1.3.3Stated by: GitHub advisory
- Sharpziplib Project SharpziplibAffected: ≥ 1.3.0, < 1.3.3Upgrade to: 1.3.3Stated by: NVD
Versions as the sources state them. Full version matrix after sign-in
What it is
From the CVE record
SharpZipLib (or #ziplib) is a Zip, GZip, Tar and BZip2 library. Starting version 1.3.0 and prior to version 1.3.3, a check was added if the destination file is under destination directory. However, it is not enforced that `destDir` ends with slash. If the `destDir` is not slash terminated like `/home/user/dir` it is possible to create a file with a name thats begins with the destination directory, i.e. `/home/user/dir.sh`. Because of the file name and destination directory constraints, the arbitrary file creation impact is limited and depends on the use case. Version 1.3.3 contains a patch for this vulnerability.
In plain language
No plain-language summary for this CVE yet.
Exploitation
Where each signal puts this CVE on the scale from published to confirmed exploited.
- CISA KEV
Not in the catalog. CISA has not confirmed exploitation.
- Public exploits
No public exploit or proof of concept found in the sources we track.
- EPSS
1.1% chance of exploitation activity in the next 30 days, which ranks it in the 65th percentile of scored CVEs.
Exploit Prediction Scoring System, FIRST.org. A probability, not a confirmation.
Lifecycle
5 events over 1030 days, from the signal feeds we watch.
- Patch availablerecord updated
- Publishedweakness classified, att&ck mapped
Affected products
Technical detail
CVSS 3.1 vector
Open in the CVSS calculatorCVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
Scored 4.0 by NVD.
How it is reached
- Attack Vector LocalRequires local access to the vulnerable system (e.g. local login, malicious file)
- Attack Complexity LowNo special conditions — the attack can be reliably reproduced
- Privileges Required NoneNo authentication required — anyone can exploit this
- User Interaction NoneNo user interaction needed — fully automated exploitation
Scope
- Scope UnchangedImpact is limited to the vulnerable component itself
Impact if exploited
- Confidentiality NoneNo confidentiality impact
- Integrity LowData modification is possible but limited in scope or consequence
- Availability NoneNo availability impact
Weaknesses
ATT&CK techniques
Mapped from the weaknesses above (CWE to ATT&CK), not observed in attacks.
Sources
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