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CVE-2023-27493

CRITICALCVSS 9.1/10EPSS 0.51%

Last modified

CVE-2023-27493 is a critical-severity vulnerability rated 9.1/10 on the CVSS scale. Envoy is an open source edge and service proxy designed for cloud-native applications. Prior to versions 1.26.0, 1.25.3, 1.24.4, 1.23.6, and 1.22.9, Envoy does not sanitize or escape request properties when generating request headers. EPSS estimates a 0.51% chance of exploitation in the next 30 days.

Description

Envoy is an open source edge and service proxy designed for cloud-native applications. Prior to versions 1.26.0, 1.25.3, 1.24.4, 1.23.6, and 1.22.9, Envoy does not sanitize or escape request properties when generating request headers. This can lead to characters that are illegal in header values to be sent to the upstream service. In the worst case, it can cause upstream service to interpret the original request as two pipelined requests, possibly bypassing the intent of Envoy’s security policy. Versions 1.26.0, 1.25.3, 1.24.4, 1.23.6, and 1.22.9 contain a patch. As a workaround, disable adding request headers based on the downstream request properties, such as downstream certificate properties.

Metrics

CVSS 3.1
9.1/10

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

EPSS Probability
0.51%

39.4th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

VendorProductVersions
EnvoyproxyEnvoy< 1.22.9
EnvoyproxyEnvoy>= 1.23.0, < 1.23.6
EnvoyproxyEnvoy>= 1.24.0, < 1.24.4
EnvoyproxyEnvoy>= 1.25.0, < 1.25.3

References

Timeline

Published
Last Modified
Status
Modified

Frequently Asked Questions

What is CVE-2023-27493?
Envoy is an open source edge and service proxy designed for cloud-native applications. Prior to versions 1.26.0, 1.25.3, 1.24.4, 1.23.6, and 1.22.9, Envoy does not sanitize or escape request properties when generating request headers. This can lead to characters that are illegal in header values to be sent to the upstream service. In the worst case, it can cause upstream service to interpret the original request as two pipelined requests, possibly bypassing the intent of Envoy’s security policy. Versions 1.26.0, 1.25.3, 1.24.4, 1.23.6, and 1.22.9 contain a patch. As a workaround, disable adding request headers based on the downstream request properties, such as downstream certificate properties.
How severe is CVE-2023-27493?
CVE-2023-27493 has a CVSS score of 9.1/10 (CRITICAL severity). The EPSS model estimates a 0.51% probability of exploitation in the next 30 days.
How do I fix CVE-2023-27493?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2023-27493?

Run a free Strix scan to check your systems for this vulnerability.

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Source: NVD / NIST