Cyber Resilience

CVE-2021-21322

Critical

Published: 02 March 2021

Published
02 March 2021
Modified
21 November 2024
KEV Added
Patch
CVSS Score v3.1 10.0 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:N
EPSS Score 0.0019 40.4th percentile
Risk Priority 20 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2021-21322 is a critical-severity Improper Input Validation (CWE-20) vulnerability in Fastify-Http-Proxy Project Fastify-Http-Proxy. Its CVSS base score is 10.0 (Critical).

Operationally, ranked at the 40.4th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

EU & UK References

Vulnerability details

fastify-http-proxy is an npm package which is a fastify plugin for proxying your http requests to another server, with hooks. By crafting a specific URL, it is possible to escape the prefix of the proxied backend service. If the base…

more

url of the proxied server is `/pub/`, a user expect that accessing `/priv` on the target service would not be possible. In affected versions, it is possible. This is fixed in version 4.3.1.

CWE(s)

Related Threats

No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.

Affected Assets

fastify-http-proxy project
fastify-http-proxy
≤ 4.3.1

Mitigating Controls

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

addresses: CWE-20

Security testing and developer training directly verify and enforce proper input validation, reducing exploitability of injection and malformed-data weaknesses.

addresses: CWE-20

Security testing and evaluation at multiple SDLC stages directly detects missing or flawed input validation, with the required remediation process ensuring fixes are applied.

addresses: CWE-20

Directly implements checks on information inputs to reject invalid data before processing.

addresses: CWE-20

Spam protection mechanisms perform filtering and detection on inbound/outbound messages, directly compensating for missing or weak input validation of unsolicited content.

References