CVE-2023-35944

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.

CVSS v3.1

5.3 MEDIUMCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N

CVSS v3.1

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

EPSS

0.70% chance of exploitation in the next 30 days, 51th percentile

Published

2023-07-25

Updated

2024-10-23

Proof-of-concept exploits (1)

• envoyproxy/envoy/security/advisories/GHSA-pvgm-7jpg-pw5g

References

• CVE Record
• NVD entry

Related

• CVE-2019-18801
• CVE-2019-18836
• CVE-2019-9900
• CVE-2022-29225
• CVE-2023-27487
• CVE-2023-27488