A flaw was found in the Secure Client Registration executor within the keycloak-services component. The vulnerability exists in the logic that enforces the signed-JWT assertion policy for client registration and updates. When the SecureSigningAlgorithmForSignedJwtExecutor is configured to require a client assertion, it only checks the alg field in the raw client assertion JWT header. It fails to validate that the client assertion type is present or that the client's actual authenticator is assertion-based. By providing a specially crafted request with an unsigned assertion header containing a valid alg field, an attacker with valid client credentials can bypass the signature verification check. This allows the attacker to successfully authenticate or update a client without providing the required cryptographic proof of identity. Successful exploitation allows an attacker to circumvent administrative security policies intended to restrict client authentication to trusted assertion-based methods.

A flaw was found in the group search functionality of the Keycloak server's administrative API. When Fine-Grained Admin Permissions (FGAP) v2 is enabled, a delegated administrator can bypass access restrictions to view parent groups they are not authorized to see. By searching for a child group they have permission to view, the system incorrectly returns the full details of the parent group in the response, leading to the disclosure of sensitive group attributes and configuration.

A flaw was identified in Keycloak, an identity and access management solution, where it improperly follows HTTP redirects when processing certain client configuration requests. This behavior allows an attacker to trick the server into making unintended requests to internal or restricted resources. As a result, sensitive internal services such as cloud metadata endpoints could be accessed. This issue may lead to information disclosure and enable attackers to map internal network infrastructure.

Duplicate Advisory This advisory has been withdrawn because it is a duplicate of GHSA-w8gr-xwp4-r9f7. This link is maintained to preserve external references.

Original Description A misconfiguration flaw was found in Keycloak. This issue can allow an attacker to redirect users to an arbitrary URL if a 'Valid Redirect URI' is set to http://localhost or http://127.0.0.1, enabling sensitive information such as authorization codes to be exposed to the attacker, potentially leading to session hijacking.

Duplicate Advisory This advisory has been withdrawn because it is a duplicate of GHSA-gc7q-jgjv-vjr2. This link is maintained to preserve external references.

Original Description A vulnerability was found in Keycloak. This flaw allows attackers to bypass brute force protection by exploiting the timing of login attempts. By initiating multiple login requests simultaneously, attackers can exceed the configured limits for failed attempts before the system locks them out. This timing loophole enables attackers to make more guesses at passwords than intended, potentially compromising account security on affected systems.

Duplicate Advisory This advisory has been withdrawn because it is a duplicate of GHSA-9vm7-v8wj-3fqw. This link is maintained to preserve external references.

Original Description A flaw was found in Keycloak. This issue may allow an attacker to steal authorization codes or tokens from clients using a wildcard in the JARM response mode "formpost.jwt" which could be used to bypass the security patch implemented to address CVE-2023-6134.

Summary

Terrapin is a prefix truncation attack targeting the SSH protocol. More precisely, Terrapin breaks the integrity of SSH's secure channel. By carefully adjusting the sequence numbers during the handshake, an attacker can remove an arbitrary amount of messages sent by the client or server at the beginning of the secure channel without the client or server noticing it.

Mitigations

To mitigate this protocol vulnerability, OpenSSH suggested a so-called "strict kex" which alters the SSH handshake to ensure a Man-in-the-Middle attacker cannot introduce unauthenticated messages as well as convey sequence number manipulation across handshakes.

Warning: To take effect, both the client and server must support this countermeasure.

As a stop-gap measure, peers may also (temporarily) disable the affected algorithms and use unaffected alternatives like AES-GCM instead until patches are available.

Details

The SSH specifications of ChaCha20-Poly1305 (chacha20-poly1305@openssh.com) and Encrypt-then-MAC (-etm@openssh.com MACs) are vulnerable against an arbitrary prefix truncation attack (a.k.a. Terrapin attack). This allows for an extension negotiation downgrade by stripping the SSHMSGEXTINFO sent after the first message after SSHMSGNEWKEYS, downgrading security, and disabling attack countermeasures in some versions of OpenSSH. When targeting Encrypt-then-MAC, this attack requires the use of a CBC cipher to be practically exploitable due to the internal workings of the cipher mode. Additionally, this novel attack technique can be used to exploit previously unexploitable implementation flaws in a Man-in-the-Middle scenario.

The attack works by an attacker injecting an arbitrary number of SSHMSGIGNORE messages during the initial key exchange and consequently removing the same number of messages just after the initial key exchange has concluded. This is possible due to missing authentication of the excess SSHMSGIGNORE messages and the fact that the implicit sequence numbers used within the SSH protocol are only checked after the initial key exchange.

In the case of ChaCha20-Poly1305, the attack is guaranteed to work on every connection as this cipher does not maintain an internal state other than the message's sequence number. In the case of Encrypt-Then-MAC, practical exploitation requires the use of a CBC cipher; while theoretical integrity is broken for all ciphers when using this mode, message processing will fail at the application layer for CTR and stream ciphers.

For more details see https://terrapin-attack.com.

Impact

This attack targets the specification of ChaCha20-Poly1305 (chacha20-poly1305@openssh.com) and Encrypt-then-MAC (-etm@openssh.com), which are widely adopted by well-known SSH implementations and can be considered de-facto standard. These algorithms can be practically exploited; however, in the case of Encrypt-Then-MAC, we additionally require the use of a CBC cipher. As a consequence, this attack works against all well-behaving SSH implementations supporting either of those algorithms and can be used to downgrade (but not fully strip) connection security in case SSH extension negotiation (RFC8308) is supported. The attack may also enable attackers to exploit certain implementation flaws in a man-in-the-middle (MitM) scenario.

A flaw was found in Keycloak that prevents certain schemes in redirects, but permits them if a wildcard is appended to the token. This issue could allow an attacker to submit a specially crafted request leading to cross-site scripting (XSS) or further attacks. This flaw is the result of an incomplete fix for CVE-2020-10748.

Duplicate Advisory This advisory has been withdrawn because it is a duplicate of GHSA-5cc8-pgp5-7mpm. This link is maintained to preserve external references.

Original Advisory A flaw was found in Keycloak. This flaw depends on a non-default configuration "Revalidate Client Certificate" to be enabled and the reverse proxy is not validating the certificate before Keycloak. Using this method an attacker may choose the certificate which will be validated by the server. If this happens and the KCSPITRUSTSTOREFILEFILE variable is missing/misconfigured, any trustfile may be accepted with the logging information of "Cannot validate client certificate trust: Truststore not available". This may not impact availability as the attacker would have no access to the server, but consumer applications Integrity or Confidentiality may be impacted considering a possible access to them. Considering the environment is correctly set to use "Revalidate Client Certificate" this flaw is avoidable.

A flaw was found in the Keycloak Node.js Adapter. This flaw allows an attacker to benefit from an Open Redirect vulnerability in the checkSso function.

A flaw was found in keycloak, where the default ECP binding flow allows other authentication flows to be bypassed. By exploiting this behavior, an attacker can bypass the MFA authentication by sending a SOAP request with an AuthnRequest and Authorization header with the user's credentials. The highest threat from this vulnerability is to confidentiality and integrity.

A flaw was found in keycloak where an attacker is able to register himself with the username same as the email ID of any existing user. This may cause trouble in getting password recovery email in case the user forgets the password.

A flaw was found in Keycloak 12.0.0 where re-authentication does not occur while updating the password. This flaw allows an attacker to take over an account if they can obtain temporary, physical access to a user’s browser. The highest threat from this vulnerability is to confidentiality, integrity, as well as system availability.

A flaw was found in keycloak as shipped in Red Hat Single Sign-On 7.4 where IDN homograph attacks are possible. A malicious user can register himself with a name already registered and trick admin to grant him extra privileges.

A flaw was found in keycloak in versions prior to 13.0.0. The client registration endpoint allows fetching information about PUBLIC clients (like client secret) without authentication which could be an issue if the same PUBLIC client changed to CONFIDENTIAL later. The highest threat from this vulnerability is to data confidentiality.

A flaw was discovered in Wildfly's EJB Client as shipped with Red Hat JBoss EAP 7, where some specific EJB transaction objects may get accumulated over the time and can cause services to slow down and eventaully unavailable. An attacker can take advantage and cause denial of service attack and make services unavailable.

A vulnerability was found in Wildfly's EJB where SessionOpenInvocations may not be removed properly after a response is received after a response is received causing Denial of Service.

A flaw was found in JBoss EAP, where the authentication configuration is set-up using a legacy SecurityRealm, to delegate to a legacy PicketBox SecurityDomain, and then reloaded to admin-only mode. This flaw allows an attacker to perform a complete authentication bypass by using an arbitrary user and password. The highest threat to vulnerability is to system availability.

A flaw was found in Keycloak's data filter, in version 10.0.1, where it allowed the processing of data URLs in some circumstances. This flaw allows an attacker to conduct cross-site scripting or further attacks.

A flaw was found in Undertow in versions before 2.1.1.Final, regarding the processing of invalid HTTP requests with large chunk sizes. This flaw allows an attacker to take advantage of HTTP request smuggling.

A flaw was found in hibernate-validator's 'isValid' method in the org.hibernate.validator.internal.constraintvalidators.hv.SafeHtmlValidator class, which can be bypassed by omitting the tag ending in a less-than character. Browsers may render an invalid html, allowing HTML injection or Cross-Site-Scripting (XSS) attacks.

A flaw was found in Keycloak 7.0.1. A logged in user can do an account email enumeration attack.

A flaw was found during the assessment of the Admin Console application for Keycloak, where it was found that Application Links to external applications are not validated properly. An attacker could use this flaw to cause Stored XSS attacks.

A flaw was discovered in all versions of Undertow before Undertow 2.2.0.Final, where HTTP request smuggling related to CVE-2017-2666 is possible against HTTP/1.x and HTTP/2 due to permitting invalid characters in an HTTP request. This flaw allows an attacker to poison a web-cache, perform an XSS attack, or obtain sensitive information from request other than their own.

A flaw was found in wildfly-core before 7.2.5.GA. The Management users with Monitor, Auditor and Deployer Roles should not be allowed to modify the runtime state of the server

A vulnerability was found in Hibernate-Validator. The SafeHtml validator annotation fails to properly sanitize payloads consisting of potentially malicious code in HTML comments and instructions. This vulnerability can result in an XSS attack.

A flaw was found in Hibernate ORM in versions before 5.3.18, 5.4.18 and 5.5.0.Beta1. A SQL injection in the implementation of the JPA Criteria API can permit unsanitized literals when a literal is used in the SELECT or GROUP BY parts of the query. This flaw could allow an attacker to access unauthorized information or possibly conduct further attacks.

A cross-site scripting (XSS) vulnerability was found in the JBoss Management Console versions before 7.1.6.CR1, 7.1.6.GA. Users with roles that can create objects in the application can exploit this to attack other privileged users.

It was found that SAML authentication in Keycloak 3.4.3.Final incorrectly authenticated expired certificates. A malicious user could use this to access unauthorized data or possibly conduct further attacks.