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Fragments in Path May Lead to Authorization Policy Bypass

High
brian-avery published GHSA-hqxw-mm44-gc4r Aug 24, 2021

Package

docker Istio (Docker)

Affected versions

<1.9.8

Patched versions

1.9.8, 1.10.4, 1.11.1

Description

Impact

Istio 1.11.0, 1.10.3 and below, and 1.9.7 and below contain a remotely exploitable vulnerability where an HTTP request with #fragment in the path may bypass Istio’s URI path based authorization policies.

Patches

  • Istio 1.11.1 and above
  • Istio 1.10.4 and above
  • Istio 1.9.8 and above

Workarounds

A Lua filter may be written to normalize the path. This is similar to the Path normalization presented in the Security Best Practices guide.

References

More details can be found in the Istio Security Bulletin

For more information

If you have any questions or comments about this advisory, please email us at istio-security-vulnerability-reports@googlegroups.com

Severity

High
8.1
/ 10

CVSS base metrics

Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
Required
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
None
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N

CVE ID

CVE-2021-39156

Weaknesses

No CWEs

Credits