CVE-2020-7777 Arbitrary Code Execution
Attackers can execute arbitrary JavaScript code by providing a malicious schema file to the jsen library, requiring immediate mitigation or replacement.
- Exploited in the wild
- Not known
- Login needed
- An administrator
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2020-7777?
CVE-2020-7777 is a high-severity code injection vulnerability in jsen, published on 23 Nov 2020. An attacker needs administrator access to exploit it, with no action from the victim.
Official description
This affects all versions of package jsen. If an attacker can control the schema file, it could run arbitrary JavaScript code on the victim machine. In the module description and README file there is no mention about the risks of untrusted schema files, so I assume that this is applicable. In particular the required field of the schema is not properly sanitized. The resulting string that is build based on the schema definition is then passed to a Function.apply();, leading to an Arbitrary Code Execution.
Which versions are affected by CVE-2020-7777?
2 open source packages ship an affected version, including jsen. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
jsen npm | All versions to 0.6.6 | None |
jsen npm | All versions to 0.6.6 | None |
Products include Jsen Project Jsen.
How do I fix CVE-2020-7777?
No fix has been published for CVE-2020-7777 yet. Limit exposure of the affected software until one is available.
Upgrade, and never evaluate templates, expressions or code built from user input. More about Code injection.
Is CVE-2020-7777 being exploited?
There is no known exploitation of CVE-2020-7777 in the wild and no public exploit code.
Sources
Also known as GHSA-vm64-cfqx-3698.