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Fencer Vulns
high 8.2

CVE-2023-27487 json

Envoy client may fake the header `x-envoy-original-path`

published 2023-04-04 3 y ago modified 2026-09-08 2 mo ago also BIT-envoy-2023-27487 , EUVD-2023-31254 , GHSA-5375-pq35-hf2g

cvss
8.2
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.6%
EPSS 0.6% chance of exploitation in 30 days, percentile 50%
public exploits
0
none known

Summary

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, the client may bypass JSON Web Token (JWT) checks and forge fake original paths. The header `x-envoy-original-path` should be an internal header, but Envoy does not remove this header from the request at the beginning of request processing when it is sent from an untrusted client. The faked header would then be used for trace logs and grpc logs, as well as used in the URL used for `jwt_authn` checks if the `jwt_authn` filter is used, and any other upstream use of the x-envoy-original-path header. Attackers may forge a trusted `x-envoy-original-path` header. Versions 1.26.0, 1.25.3, 1.24.4, 1.23.6, and 1.22.9 have patches for this issue.

Patch / fix

  • bitnami envoy 1.22.9, 1.23.6, 1.24.4, 1.25.3
  • envoyproxy envoy 1.22.9, 1.23.6, 1.24.4, 1.25.3

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2023-27487 updated cvss 8.2

envoy: Client may fake the header `x-envoy-original-path`

  • Red Hat OpenShift Service Mesh 2.1 servicemesh-proxy, servicemesh-proxy-wasm
    affected: no fix available
  • Red Hat RHOSSM 2.2 for RHEL 8 openshift-service-mesh/proxyv2-rhel8 2.2.9-2
    fixed: vendor fix RHSA-2023:4623
  • Red Hat RHOSSM 2.2 for RHEL 8 openshift-service-mesh/pilot-rhel8 2.2.9-1, openshift-service-mesh/grafana-rhel8 2.2.9-1, openshift-service-mesh/istio-cni-rhel8 2.2.9-1, openshift-service-mesh/ratelimit-rhel8 2.2.9-1, openshift-service-mesh/prometheus-rhel8 2.2.9-1, openshift-service-mesh/istio-must-gather-rhel8 2.2.9-2
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
Proof of concept is public
Automatable
yes
Technical impact
partial
Assessed
20 mo ago

Exploit prediction

0.64% chance of exploitation in the next 30 days, higher than 50% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • github.com https://github.com/envoyproxy/envoy/security/advisories/GHSA-5375-pq35-hf2g referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 3.1 8.2 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N
NVD 3.1 9.1 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
OSV 3.1 9.1 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

Affected packages

ecosystem package affected fixed in
bitnami envoy
<1.22.9
>=1.23.0, <1.23.6
>=1.24.0, <1.24.4
>=1.25.0, <1.25.3
1.22.9
1.23.6
1.24.4
1.25.3

Affected products

  • envoyproxy envoy

Classification

Weakness
  • CWE-20 Improper Input Validation

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.