CVE-2018-20835 Improper Input Validation in tar-fs
An attacker can overwrite arbitrary files on the system by crafting a malicious tarball with specific hardlink structures, affecting applications using the tar-fs library.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2018-20835?
CVE-2018-20835 is a high-severity path traversal vulnerability in n/a, published on 30 Apr 2019. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
A vulnerability was found in tar-fs before 1.16.2. An Arbitrary File Overwrite issue exists when extracting a tarball containing a hardlink to a file that already exists on the system, in conjunction with a later plain file with the same name as the hardlink. This plain file content replaces the existing file content.
Weakness: CWE-20
Which versions are affected by CVE-2018-20835?
2 open source packages ship an affected version, including tar-fs. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
tar-fs npm | All versions | 1.16.2 |
tar-fs npm | All versions | 1.16.2 |
Products include Tar-Fs Project Tar-Fs.
How do I fix CVE-2018-20835?
Upgrade tar-fs to 1.16.2 or later.
Upgrade, and resolve every user-supplied path against an allowed base folder before opening it. More about Path traversal.
Is CVE-2018-20835 being exploited?
There is no known exploitation of CVE-2018-20835 in the wild and no public exploit code.
Sources
Also known as GHSA-x2mc-8fgj-3wmr.