qs before 6.10.3, as used in Express before 4.17.3 and other products, allows attackers to cause a Node process hang for an Express application because an __ proto__ key can be used. In many typical Express use cases, an unauthenticated remote attacker can place the attack payload in the query string of the URL that is used to visit the application, such as a[__proto__]=b&a[__proto__]&a[length]=100000000. The fix was backported to qs 6.9.7, 6.8.3, 6.7.3, 6.6.1, 6.5.3, 6.4.1, 6.3.3, and 6.2.4 (and therefore Express 4.17.3, which has "deps: qs@6.9.7" in its release description, is not vulnerable).
The product receives input from an upstream component that specifies attributes that are to be initialized or updated in an object, but it does not properly control modifications of attributes of the object prototype.
| Link | Tags |
|---|---|
| https://github.com/expressjs/express/releases/tag/4.17.3 | release notes |
| https://github.com/ljharb/qs/pull/428 | issue tracking patch |
| https://github.com/n8tz/CVE-2022-24999 | third party advisory exploit |
| https://lists.debian.org/debian-lts-announce/2023/01/msg00039.html | third party advisory mailing list |
| https://security.netapp.com/advisory/ntap-20230908-0005/ |