fast-toml through 0.5.4 contains a prototype pollution vulnerability that allows attackers to modify Object.prototype by supplying TOML containing __proto__, constructor or prototype key segments. Attackers can pass [__proto__] or [constructor.prototype] table headers or __proto__.x dotted keys to parse() to pollute all objects, causing denial of service or authorization bypass.
Attack Parameters
Attack Vector
Network
Can be exploited remotely
Attack Complexity
Low
Easy to exploit
Attack Requirements
None
No additional conditions
Privileges Required
None
No privileges needed
User Interaction
None
No user interaction needed
Impact Assessment
Confidentiality
None
No data leak
Integrity
High
Complete data modification
Availability
Low
Partial disruption
CVSS Vector v4.0
Weakness Type (CWE)
References 4
https://github.com/Gin-Quin/fast-toml
disclosure@vulncheck.com
https://github.com/Gin-Quin/fast-toml/issues/8
disclosure@vulncheck.com
https://github.com/Gin-Quin/fast-toml/pull/3
disclosure@vulncheck.com
https://www.vulncheck.com/advisories/fast-toml-through-0.5.4-prototype-pollutio…
disclosure@vulncheck.com