CVE-2021-22113Network attack vector

Sensitive-header bypass via noncanonical request paths

Published Feb 23, 2021 · Updated Aug 3, 2024

Incorrect authorization in Spring Cloud Netflix Zuul 2.2.6 and earlier allows remote attackers to bypass sensitive-header filtering with crafted URLs. PreDecorationFilter matched routing policy against a noncanonical request path without first rejecting encoded or traversal-like segments, so a backend could receive headers that the intended route marked sensitive. Exposure requires the Sensitive Headers feature and a path not rejected by Spring Security's default StrictHttpFirewall; impact is limited to unauthorized forwarding of filtered headers.

CVSS severity5.3
Medium
EPSS probability0.85%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Incorrect authorization in Spring Cloud Netflix Zuul 2.2.6 and earlier allows remote attackers to bypass sensitive-header filtering with crafted URLs. PreDecorationFilter matched routing policy against a noncanonical request path without first rejecting encoded or traversal-like segments, so a backend could receive headers that the intended route marked sensitive. Exposure requires the Sensitive Headers feature and a path not rejected by Spring Security's default StrictHttpFirewall; impact is limited to unauthorized forwarding of filtered headers.

The record

CVE
CVE-2021-22113
Published
Feb 23, 2021
Updated
Aug 3, 2024
Vendor
VMware
Product
Spring Cloud Netflix Zuul
Classifications
CWE-863, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Feb 23, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=2.2.6 and below

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

VMware · Spring Cloud Netflix Zuulversion=2.2.6 and below

Published CVSS scores

5.3NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
4.3NIST NVDAV:N/AC:M/Au:N/C:N/I:P/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-863Incorrect Authorization
T1190Exploit Public-Facing Application

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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