Open-Source Security Intelligence

Know every vulnerability
before it knows you.

DevGuard continuously monitors your dependencies and alerts you when CVEs like this one affect your stack — with real-time threat intelligence built for developers.

Search

GHSA-jp7f-grcv-6mjf

MediumCVSS 4.3 / 10
Published Sep 20, 2021·Last modified Mar 13, 2026
Affected Components(0)

No affected components available

Description

SharpCompress recreates a hierarchy of directories under destinationDirectory if ExtractFullPath is set to true in options. In order to prevent extraction outside the destination directory the destinationFileName path is verified to begin with fullDestinationDirectoryPath. However it is not enforced that fullDestinationDirectoryPath ends with slash:

public static void WriteEntryToDirectory(IEntry entry,
                                         string destinationDirectory,
                                         ExtractionOptions? options,
                                         Action<string, ExtractionOptions?> write)
{
    string destinationFileName;
    string file = Path.GetFileName(entry.Key);
    string fullDestinationDirectoryPath = Path.GetFullPath(destinationDirectory);
...
        throw new ExtractionException("Entry is trying to write a file outside of the destination directory.");
}

If the destinationDirectory is not slash terminated like /home/user/dir it is possible to create a file with a name thats begins as the destination directory one level up from the directory, i.e. /home/user/dir.sh.

Impact

Because of the file name and destination directory constraints the arbitrary file creation impact is limited and depends on the use case.

Risk Scores
Base Score
4.3

The vulnerability can be exploited over the network without needing physical access. It is easy for an attacker to exploit this vulnerability. An attacker needs basic access or low-level privileges. No user interaction is needed for the attacker to exploit this vulnerability. The impact is confined to the system where the vulnerability exists. There is a low impact on the integrity of the data.

Threat Intelligence
4.0

Exploitation attempts have been detected. Elevated vigilance and prompt remediation are advised.

EPSS
1.19%

The exploit probability is very low. The vulnerability is unlikely to be exploited in the next 30 days.

Exploit
Not available

We did not find any exploit available. Neither in GitHub repositories nor in the Exploit-Database.

Browse More

Scan your project

Continuously monitor your dependencies and get alerted when vulnerabilities like this one affect your stack.

Checkout DevGuard