Interpreter crash via unbounded expression recursion
Published May 28, 2021 · Updated Aug 4, 2024
Stack exhaustion in Cesanta MJS 1.20.1 allows remote attackers to crash the interpreter by supplying a crafted JavaScript file. The parser accepts deeply nested array expressions without a nesting limit, repeatedly cycling from parse_unary through the expression-parser chain and back into parse_array_literal until the native call stack is exhausted. Exploitation requires an embedding application to pass attacker-controlled JavaScript to MJS, and the demonstrated consequence is termination of the interpreter process.
Summary
What happened
Stack exhaustion in Cesanta MJS 1.20.1 allows remote attackers to crash the interpreter by supplying a crafted JavaScript file. The parser accepts deeply nested array expressions without a nesting limit, repeatedly cycling from parse_unary through the expression-parser chain and back into parse_array_literal until the native call stack is exhausted. Exploitation requires an embedding application to pass attacker-controlled JavaScript to MJS, and the demonstrated consequence is termination of the interpreter process.
The record
- CVE
- CVE-2020-36370
- Published
- May 28, 2021
- Updated
- Aug 4, 2024
- Vendor
- Unknown vendor
- Product
- Unknown product
- Classifications
- CWE-674, T1499.004
- Attack vector
- local
- Privileges
- unauthenticated
Timeline
How it unfolded
- May 28, 2021CVE publishedPublication date reported by the CVE source.
- Aug 4, 2024Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
Compare your product and version with the public record. A matching version still requires validation against your environment.
Is a vulnerable build present?
What conditions does exploitation require?
What is affected?
Affected products and versions are unavailable in this record.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- Crafted nested-array JavaScript proof of conceptproof of concept · demonstrated
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
See the directory against your own environment.
Your stack
Check the software in your environment
Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.
Book a demo