SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityModified

CVE-2020-7777

If an attacker can control the schema file, it could run arbitrary JavaScript code on the victim machine.

HIGH 7.2EPSS 2.11%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (2.11%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

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.

CVSS 3.1
7.2 HIGHCVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
EPSS
2.11% probability · 81th percentile
CISA KEV
Not listed
Affected
jsen project/jsen
Source
report@snyk.io

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.