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CVE-2023-35944

Envoy vulnerable to incorrect handling of HTTP requests and responses with mixed case schemes

Published
Last modified
published
Not listed in CISA KEV
Fix
Fixed in 1.26.4, 1.25.9, 1.24.10, 1.23.12
None on Exploit-DB, Metasploit or GitHub
  • Exploitation: poc
  • Automatable: no
  • Technical impact: total

Summary

Envoy is an open source edge and service proxy designed for cloud-native applications. Envoy allows mixed-case schemes in HTTP/2, however, some internal scheme checks are case-sensitive. Prior to versions 1.27.0, 1.26.4, 1.25.9, 1.24.10, and 1.23.12, this can lead to the rejection of requests with mixed-case schemes such as `htTp` or `htTps`, or the bypassing of some requests such as `https` in unencrypted connections. With a fix in versions 1.27.0, 1.26.4, 1.25.9, 1.24.10, and 1.23.12, Envoy will now lowercase scheme values by default, and change the internal scheme checks that were case-sensitive to be case-insensitive. There are no known workarounds for this issue.

Timeline

  1. CVE published
  2. CISA SSVC assessment

    Exploitation: poc · Automatable: no · Technical impact: total

  3. Record last updated

Affected versions

  • envoyproxy envoy

    From 1.26.0 · fixed in 1.26.4; From 1.25.0 · fixed in 1.25.9; From 1.24.0 · fixed in 1.24.10; fixed in 1.23.12

References 1

GitHub · envoyproxy/envoy