Jenkins 2.441 and earlier, LTS 2.426.2 and earlier does not disable a feature of its CLI command parser that replaces an '@' character followed by a file path in an argument with the file's contents, allowing unauthenticated attackers to read arbitrary files on the Jenkins controller file system.

A code execution vulnerability exists in the Stapler web framework used by Jenkins

The remoting module in Jenkins before 2.32 and LTS before 2.19.3 allows remote attackers to execute arbitrary code via a crafted serialized Java object, which triggers an LDAP query to a third-party server.

Jenkins contains a remote code execution vulnerability. This vulnerability that could allowed attackers to transfer a serialized Java SignedObject object to the remoting-based Jenkins CLI, that would be deserialized using a new ObjectInputStream, bypassing the existing blocklist-based protection mechanism.

Jenkins 2.217 through 2.441 (both inclusive), LTS 2.222.1 through 2.426.2 (both inclusive) does not perform origin validation of requests made through the CLI WebSocket endpoint, resulting in a cross-site WebSocket hijacking (CSWSH) vulnerability, allowing attackers to execute CLI commands on the Jenkins controller.

Jenkins 2.554 and earlier, LTS 2.541.2 and earlier does not safely handle symbolic links during the extraction of .tar and .tar.gz archives, allowing crafted archives to write files to arbitrary locations on the filesystem, restricted only by file system access permissions of the user running Jenkins. This can be exploited to deploy malicious scripts or plugins on the controller by attackers with Item/Configure permission, or able to control agent processes.

In Jenkins 2.567 and earlier, LTS 2.555.2 and earlier, it is possible for attackers to have Jenkins deserialize arbitrary types defined in Jenkins core or plugins from an attacker-controlled config.xml submission in a way that allows them to handle HTTP requests afterwards. This can be used to impersonate any user and send HTTP requests on their behalf, up to and including use of the Script Console to run arbitrary code, or to read arbitrary files from the Jenkins controller.

Rejected reason: This CVE ID has been rejected or withdrawn by its CVE Numbering Authority.

In Jenkins 2.579 and earlier, LTS 2.568.2 and earlier, objects of types marked as storing their configuration in independent top-level configuration files in Jenkins (such as the global configuration and jobs) can appear as nested field values in user-submitted config.xml documents and subsequently handle HTTP requests via Stapler, resulting in remote code execution.

In Jenkins 2.579 and earlier, LTS 2.568.2 and earlier, the system log viewer does not escape log record metadata (source, level, and timestamp) resulting in a stored cross-site scripting (XSS) vulnerability exploitable by attackers in control of agent processes.

In Stapler 2107.v8dfcbe8ed317 and earlier, except 2088.2093.vd7c3e58008a6, included in Jenkins 2.579 and earlier, LTS 2.568.2 and earlier, Stapler does not restrict the types of objects that can be instantiated via form data binding to those compatible with the expected field type, allowing attackers with Overall/Read permission to instantiate types related to configuration for which that field type was not intended.

In Jenkins 2.579 and earlier, LTS 2.568.2 and earlier, transient fields cannot be excluded from deserialization, allowing attackers able to submit configuration updates to specify the values of transient fields that will be deserialized, the impact depending on how those fields are used.

Jenkins main before 1.482 and LTS before 1.466.2 allows remote attackers with read access and HTTP access to Jenkins master to insert data and execute arbitrary code.

Jenkins Katalon Plugin 1.0.32 and earlier implements an agent/controller message that does not limit where it can be executed and allows invoking Katalon with configurable arguments, allowing attackers able to control agent processes to invoke Katalon on the Jenkins controller with attacker-controlled version, install location, and arguments, and attackers additionally able to create files on the Jenkins controller (e.g., attackers with Item/Configure permission could archive artifacts) to invoke arbitrary OS commands.

An extension point in Jenkins allows selectively disabling cross-site request forgery (CSRF) protection for specific URLs.

Implementations of that extension point received a different representation of the URL path than the Stapler web framework uses to dispatch requests in Jenkins 2.227 and earlier, LTS 2.204.5 and earlier. This discrepancy allowed attackers to craft URLs that would bypass the CSRF protection of any target URL.

Jenkins now uses the same representation of the URL path to decide whether CSRF protection is needed for a given URL as the Stapler web framework uses.

In case of problems, administrators can disable this security fix by setting the system property hudson.security.csrf.CrumbFilter.UNPROCESSEDPATHINFO to true.

As an additional safeguard, semicolon (;) characters in the path part of a URL are now banned by default. Administrators can disable this protection by setting the system property jenkins.security.SuspiciousRequestFilter.allowSemicolonsInPath to true.

Jenkins 2.213 and earlier, LTS 2.204.1 and earlier improperly reuses encryption key parameters in the Inbound TCP Agent Protocol/3, allowing unauthorized attackers with knowledge of agent names to obtain the connection secrets for those agents, which can be used to connect to Jenkins, impersonating those agents.

Jenkins 2.575 and earlier, LTS 2.568.1 and earlier handles case-insensitivity in user names and group names inconsistently, allowing attackers able to create new users or groups with names that case-insensitively match other characters to impersonate other users or be granted their permissions in some circumstances.

Jenkins 2.483 through 2.550 (both inclusive), LTS 2.492.1 through 2.541.1 (both inclusive) does not escape the user-provided description of the "Mark temporarily offline" offline cause, resulting in a stored cross-site scripting (XSS) vulnerability exploitable by attackers with Agent/Configure or Agent/Disconnect permission.

A flaw was found in jenkins. Users with Agent/Configure permissions can choose agent names that cause an override to the global config.xml file. The highest threat from this vulnerability is to data confidentiality and integrity as well as system availability.

A flaw was found in jenkins. An attacker with permission to create or configure various objects to inject crafted content into Old Data Monitor can cause the instantiation of potentially unsafe objects once discarded by an administrator. The highest threat from this vulnerability is to data confidentiality and integrity as well as system availability.

Jenkins 2.367 through 2.369 (both inclusive) does not escape tooltips of the l:helpIcon UI component used for some help icons on the Jenkins web UI, resulting in a stored cross-site scripting (XSS) vulnerability exploitable by attackers able to control tooltips for this component.

As of publication, the Jenkins security team is unaware of any exploitable help icon/tooltip in Jenkins core or plugins published by the Jenkins project. The vast majority of help icons use the l:help component instead of l:helpIcon. The few known instances of l:helpIcon do not have user-controllable tooltip contents.

In Jenkins 2.399 and earlier, LTS 2.387.3 and earlier, POST requests are sent in order to load the list of context actions. If part of the URL includes insufficiently escaped user-provided values, a victim may be tricked into sending a POST request to an unexpected endpoint by opening a context menu.

Impact When using SSL/TLS with Jetty, either with HTTP/1.1, HTTP/2, or WebSocket, the server may receive an invalid large (greater than 17408) TLS frame that is incorrectly handled, causing CPU resources to eventually reach 100% usage.

Workarounds

The problem can be worked around by compiling the following class: java package org.eclipse.jetty.server.ssl.fix6072;

import java.nio.ByteBuffer; import javax.net.ssl.SSLEngine; import javax.net.ssl.SSLEngineResult; import javax.net.ssl.SSLException; import javax.net.ssl.SSLHandshakeException;

import org.eclipse.jetty.io.EndPoint; import org.eclipse.jetty.io.ssl.SslConnection; import org.eclipse.jetty.server.Connector; import org.eclipse.jetty.server.SslConnectionFactory; import org.eclipse.jetty.util.BufferUtil; import org.eclipse.jetty.util.annotation.Name; import org.eclipse.jetty.util.ssl.SslContextFactory;

public class SpaceCheckingSslConnectionFactory extends SslConnectionFactory { public SpaceCheckingSslConnectionFactory(@Name("sslContextFactory") SslContextFactory factory, @Name("next") String nextProtocol) { super(factory, nextProtocol); }

@Override protected SslConnection newSslConnection(Connector connector, EndPoint endPoint, SSLEngine engine) { return new SslConnection(connector.getByteBufferPool(), connector.getExecutor(), endPoint, engine, isDirectBuffersForEncryption(), isDirectBuffersForDecryption()) { @Override protected SSLEngineResult unwrap(SSLEngine sslEngine, ByteBuffer input, ByteBuffer output) throws SSLException { SSLEngineResult results = super.unwrap(sslEngine, input, output);

if ((results.getStatus() == SSLEngineResult.Status.BUFFERUNDERFLOW || results.getStatus() == SSLEngineResult.Status.OK && results.bytesConsumed() == 0 && results.bytesProduced() == 0) && BufferUtil.space(input) == 0) { BufferUtil.clear(input); throw new SSLHandshakeException("Encrypted buffer max length exceeded"); } return results; } }; } } This class can be deployed by: + The resulting class file should be put into a jar file (eg sslfix6072.jar) + The jar file should be made available to the server. For a normal distribution this can be done by putting the file into ${jetty.base}/lib + Copy the file ${jetty.home}/modules/ssl.mod to ${jetty.base}/modules + Edit the ${jetty.base}/modules/ssl.mod file to have the following section:

[lib] lib/sslfix6072.jar

+ Copy the file ${jetty.home}/etc/jetty-https.xml and${jetty.home}/etc/jetty-http2.xml to ${jetty.base}/etc + Edit files ${jetty.base}/etc/jetty-https.xml and ${jetty.base}/etc/jetty-http2.xml, changing any reference of org.eclipse.jetty.server.SslConnectionFactory to org.eclipse.jetty.server.ssl.fix6072.SpaceCheckingSslConnectionFactory. For example: xml <Call name="addIfAbsentConnectionFactory"> <Arg> <New class="org.eclipse.jetty.server.ssl.fix6072.SpaceCheckingSslConnectionFactory"> <Arg name="next">http/1.1</Arg> <Arg name="sslContextFactory"><Ref refid="sslContextFactory"/></Arg> </New> </Arg> </Call> + Restart Jetty

Jenkins User Interface (UI) contains an information disclosure vulnerability that allows users to see the names of jobs and builds otherwise inaccessible to them on the "Fingerprints" pages.

Jenkins 2.540 and earlier, LTS 2.528.2 and earlier does not properly close HTTP-based CLI connections when the connection stream becomes corrupted, allowing unauthenticated attackers to cause a denial of service.

Jenkins 2.442 through 2.554 (both inclusive), LTS 2.426.3 through LTS 2.541.2 (both inclusive) performs origin validation of requests made through the CLI WebSocket endpoint by computing the expected origin for comparison using the Host or X-Forwarded-Host HTTP request headers, making it vulnerable to DNS rebinding attacks that allow bypassing origin validation.

Jenkins 2.299 and earlier, LTS 2.289.1 and earlier does not invalidate the previous session on login.

Description Invalid HTTP/2 requests (for example, invalid URIs) are incorrectly handled by writing a blocking error response directly from the selector thread. If the client manages to exhaust the HTTP/2 flow control window, or TCP congest the connection, the selector thread will be blocked trying to write the error response. If this is repeated for all the selector threads, the server becomes unresponsive, causing the denial of service.

Impact A malicious client may render the server unresponsive.

Patches The fix is available in Jetty versions 9.4.47. 10.0.10, 11.0.10.

Workarounds No workaround available within Jetty itself. One possible workaround is to filter the requests before sending them to Jetty (for example in a proxy)

For more information If you have any questions or comments about this advisory: Email us at security@webtide.com.

The API token-issuing service in Jenkins before 1.606 and LTS before 1.596.2 allows remote attackers to gain privileges via a "forced API token change" involving anonymous users.

HTTP/2 Rapid reset attack The HTTP/2 protocol allows clients to indicate to the server that a previous stream should be canceled by sending a RSTSTREAM frame. The protocol does not require the client and server to coordinate the cancellation in any way, the client may do it unilaterally. The client may also assume that the cancellation will take effect immediately when the server receives the RSTSTREAM frame, before any other data from that TCP connection is processed.

Abuse of this feature is called a Rapid Reset attack because it relies on the ability for an endpoint to send a RSTSTREAM frame immediately after sending a request frame, which makes the other endpoint start working and then rapidly resets the request. The request is canceled, but leaves the HTTP/2 connection open.

The HTTP/2 Rapid Reset attack built on this capability is simple: The client opens a large number of streams at once as in the standard HTTP/2 attack, but rather than waiting for a response to each request stream from the server or proxy, the client cancels each request immediately.

The ability to reset streams immediately allows each connection to have an indefinite number of requests in flight. By explicitly canceling the requests, the attacker never exceeds the limit on the number of concurrent open streams. The number of in-flight requests is no longer dependent on the round-trip time (RTT), but only on the available network bandwidth.

In a typical HTTP/2 server implementation, the server will still have to do significant amounts of work for canceled requests, such as allocating new stream data structures, parsing the query and doing header decompression, and mapping the URL to a resource. For reverse proxy implementations, the request may be proxied to the backend server before the RSTSTREAM frame is processed. The client on the other hand paid almost no costs for sending the requests. This creates an exploitable cost asymmetry between the server and the client.

Multiple software artifacts implementing HTTP/2 are affected. This advisory was originally ingested from the swift-nio-http2 repo advisory and their original conent follows.

swift-nio-http2 specific advisory swift-nio-http2 is vulnerable to a denial-of-service vulnerability in which a malicious client can create and then reset a large number of HTTP/2 streams in a short period of time. This causes swift-nio-http2 to commit to a large amount of expensive work which it then throws away, including creating entirely new Channels to serve the traffic. This can easily overwhelm an EventLoop and prevent it from making forward progress.

swift-nio-http2 1.28 contains a remediation for this issue that applies reset counter using a sliding window. This constrains the number of stream resets that may occur in a given window of time. Clients violating this limit will have their connections torn down. This allows clients to continue to cancel streams for legitimate reasons, while constraining malicious actors.