Keycloak
CVE-2017-12158
MEDIUM
Vulnerability Assessment
| Weakness |
CWE
OWASP Top 10:2025
A06:2025 - Insecure Design
ASVS 5.0
V4 - API and Web Service HTTP request consistency
|
| Impact | CVSS score of 5.4 (MEDIUM). Attack characteristics: network attack vector, low complexity, low privileges required, user interaction required. EPSS exploitation probability: 0.67%. |
| Exploit ScenarioDerived | A remote attacker could manipulate HTTP request interpretation between frontend and backend servers by sending crafted requests to the affected application. |
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Alert meAnalysisAI
It was found that Keycloak would accept a HOST header URL in the admin console and use it to determine web resource locations. Rated medium severity (CVSS 5.4), this vulnerability is remotely exploitable, low attack complexity. This HTTP Request/Response Smuggling vulnerability could allow attackers to manipulate HTTP request interpretation between frontend and backend servers.
RemediationAI
A vendor patch is available. Apply the latest security update as soon as possible. Enforce strict HTTP parsing, normalize requests at proxy layer, use HTTP/2 end-to-end, reject ambiguous headers.
Affected Packages
Source: OSV (Open Source Vulnerabilities)
Affects your stack
Affects 1 package in maven
Checking this CVE against your own stacks and servers is part of the Basic plan and up.
Technical ContextAI · show details
This vulnerability is classified as HTTP Request/Response Smuggling (CWE-444), which allows attackers to manipulate HTTP request interpretation between frontend and backend servers. It was found that Keycloak would accept a HOST header URL in the admin console and use it to determine web resource locations. An attacker could use this flaw against an authenticated user to attain reflected XSS via a malicious server. Affected products include: Redhat Single Sign On, Keycloak.
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Severity by source
AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
Primary rating from NVD · only source for this CVE.
CVSS VectorNVD
DescriptionCVE.org
It was found that Keycloak would accept a HOST header URL in the admin console and use it to determine web resource locations. An attacker could use this flaw against an authenticated user to attain reflected XSS via a malicious server.
Threat Intelligence Overview
NVD
CVE.org
EPSS
How this decision was reached
The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.
What every action level means
SSVC AssessmentENISA
Priority Score
Attack Technique
Cross-Site Scripting occurs when an application accepts untrusted data and sends it to a web browser without proper validation or encoding.
HTTP request smuggling exploits inconsistencies in how front-end and back-end servers parse HTTP message boundaries.
Affected Products (CPE)CVE.org
The SSH transport protocol with certain OpenSSH extensions, found in OpenSSH before 9.6 and other products, allows remot
The org.keycloak.services.resources.SocialResource.callback method in JBoss KeyCloak before 1.0.3.Final allows remote at
An unconstrained memory consumption vulnerability was discovered in Keycloak. Rated high severity (CVSS 7.7), this vulne
Due to improper authorization, Red Hat Single Sign-On is vulnerable to users performing actions that they should not be
It was found that the Keycloak Node.js adapter 2.5 - 3.0 did not handle invalid tokens correctly. Rated critical severit
Authentication bypass in the Apache Airflow Keycloak auth manager provider (apache-airflow-providers-keycloak below 0.10
A privilege escalation flaw was found in the token exchange feature of keycloak. Rated critical severity (CVSS 9.8), thi
A vulnerability was found in keycloak 7.x, when keycloak is configured with LDAP user federation and StartTLS is used in
A flaw was found in keycloak in versions before 13.0.0. Rated critical severity (CVSS 9.6), this vulnerability is remote
A flaw was found in Keycloak that prevents certain schemes in redirects, but permits them if a wildcard is appended to t
A flaw was found in Keycloak. Rated medium severity (CVSS 5.4), this vulnerability is remotely exploitable, low attack c
A flaw was found in Keycloak before 13.0.0, where it is possible to force the server to call out an unverified URL using
GitHub PoC
Exploit-DB