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CVE-2023-35944

HIGH severity · CVSS 8.2 · Improper input validation
8.2CVSS HIGH

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.

Impact & exploitability

Attack vectorNetwork
Attack complexityLow
Privileges requiredNone
User interactionNone
Confidentiality impactHigh
Integrity impactLow
Availability impactNone
Exploit probability (EPSS)1%

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N

Affected products we track (1)

Recommendation

Apply the vendor fix promptly. Open any affected product above for its exact safe version.