Vulnerability Report

CVE-2023-35944

Title: Mixed-Case Scheme Bypass/Rejection in Envoy HTTP/2

Security Bypass/Denial of Service

Proof Of Concept

No public PoC currently indexed for CVE-2023-35944.

CWE Category CWE-444
Published Date Jul 25, 2023
Modified Date Nov 21, 2024
Exploit Status Not Found
Score 8.2 CVSS v3.1
Exploit Probability (EPSS)
0.60%

Vulnerability Summary

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.

Impacted Vendors

E
enphase 1
E
envoyproxy 1

Reference Links

https://github.com/envoyproxy/envoy/security/advisories/GHSA-pvgm-7jpg-pw5g https://github.com/envoyproxy/envoy/security/advisories/GHSA-pvgm-7jpg-pw5g
CVSS v3.1
Source Entity [email protected]
Severity HIGH
8.2
Attack Vector
NETWORK
Complexity
LOW
Privileges
N/A
Interaction
NONE
Confidentiality
N/A
Integrity
N/A
Availability
N/A
Scope
UNCHANGED
RAW VECTOR CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N
CVSS v3.1
Source Entity [email protected]
Severity MEDIUM
5.3
Attack Vector
NETWORK
Complexity
LOW
Privileges
N/A
Interaction
NONE
Confidentiality
N/A
Integrity
N/A
Availability
N/A
Scope
UNCHANGED
RAW VECTOR CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N

Associated Attack Patterns (CAPEC)

Total: Patterns

CVE-2023-35944 Exploits & PoCs (Proof Of Concept)

No public PoCs found in our database for this CVE.

MODIFIED

Vulnerability data or affected products updated.

PUBLISHED

Vulnerability first announced in NVD.

Attack Vector Matrix

Access Vector NETWORK
Complexity LOW
Privileges N/A
Interaction NONE
CVSS Vector String CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N

Affected Stack

No specific products linked.