GHSA-wp97-x4hv-qvhp: High severity npm/seroval vulnerability
Summary
fromJSON and fromCrossJSON did not check that an array node's element list is an array. A small crafted payload could set the length the decoder used. That length controlled how much memory was allocated and how many times the decoder looped, and it did not depend on the size of the payload.
Impact
A service that passes untrusted input to fromJSON or fromCrossJSON can be made unavailable by an unauthenticated request.
- A small payload can allocate enough memory to end the process. - A small payload can block the thread for seconds, or without end.
This affects any framework that decodes request bodies with these functions before its own validation runs.
This issue is a bypass of the fix for GHSA-66fc-rw6m-c2q6 in 1.4.1.
Patches
Fixed in seroval@1.6.8. The deserializer now rejects any node whose element list is not an array, and throws SerovalMalformedNodeError.
Workarounds
None. Upgrade to 1.6.8.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
npm/serovalto a version that resolves this vulnerability.Fixed in 1.6.8 - Upgrade
Upgrade
serovalto a version that resolves this vulnerability.Fixed in 1.6.8
Event History
Frequently Asked Questions
Which deployments are exposed to denial of service?
Any service that passes untrusted input to seroval's fromJSON or fromCrossJSON functions is exposed. This includes frameworks that deserialize request bodies with these functions before their own validation runs.
What does an attacker need to exploit this issue?
An attacker can trigger the issue with an unauthenticated request containing a small crafted payload. The payload can cause excessive memory allocation or make a decoder thread loop for seconds or indefinitely.
Are there mitigations if upgrading cannot happen immediately?
No workaround is provided. Upgrade seroval to version 1.6.8.
How does the fixed version handle malformed input?
Version 1.6.8 rejects nodes whose element list is not an array and throws SerovalMalformedNodeError.