Cyber Resilience

CVE-2021-33570

MediumPublic PoC

Published: 25 May 2021

Published
25 May 2021
Modified
21 November 2024
KEV Added
Patch
CVSS Score v3.1 5.4 CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
EPSS Score 0.0069 72.2th percentile
Risk Priority 11 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2021-33570 is a medium-severity Cross-site Scripting (CWE-79) vulnerability in Postbird Project Postbird. Its CVSS base score is 5.4 (Medium).

Operationally, ranked in the top 27.8% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

EU & UK References

Vulnerability details

Postbird 0.8.4 allows stored XSS via the onerror attribute of an IMG element in any PostgreSQL database table. This can result in reading local files via vectors involving XMLHttpRequest and open of a file:/// URL, or discovering PostgreSQL passwords via…

more

vectors involving Window.localStorage and savedConnections.

CWE(s)

Related Threats

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

Affected Assets

postbird project
postbird
0.8.4

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-79

Penetration testing submits XSS payloads to web applications, detecting cross-site scripting flaws for subsequent remediation.

addresses: CWE-79

Validates web inputs to reject script-related content that could produce XSS.

addresses: CWE-79

Output validation against expected content can reject or sanitize script content in generated web pages, reducing XSS exploitability.

References