A flaw was found in Apache Santuario (XML Security for Java) in the way it processed some paths. A remote attacker could use this flaw to circumvent the "secure validation" feature and disclose potentially sensitive information in local XML files.

An unspecified vulnerability in Java SE related to the JNDI component could allow an unauthenticated attacker to cause no confidentiality impact, low integrity impact, and no availability impact.

An unspecified vulnerability in Java SE related to the Libraries component could allow an unauthenticated attacker to cause no confidentiality impact, low integrity impact, and no availability impact.

Eclipse Jetty is vulnerable to a denial of service, caused by an error related to some of the production servers spiking with CPU use. A remote attacker could exploit this vulnerability to consume CPU that remains high even without any traffic.

An unspecified vulnerability in Java SE related to the JAXP component could allow an unauthenticated attacker to cause a denial of service resulting in a low availability impact using unknown attack vectors.

A flaw was found in the Serialization component of OpenJDK. A reference to an uninitialized class descriptor encountered during object stream deserialization could cause an unexpected exception to be raised when processing an untrusted serialized input.

A flaw was found in the Nashorn JavaScript engine in the Scripting component of OpenJDK. The state machine of the regular expression Parser did not correctly handle empty string nodes in certain cases, which could cause an unexpected exception to be raised when processing a specially crafted regular expression.

A flaw was found in the Serialization component of OpenJDK. The invokeWriteObject() method of the ObjectStreamClass method failed to catch InstantiationError exception during object stream deserialization, which could cause an unexpected exception to be raised when processing an untrusted serialized input.

A flaw was found in the Security component of OpenJDK. It was discovered that the unmarshalKeyInfo() method of the DOMKeyInfoFactory class and the unmarshalXMLSignature() method of the DOMXMLSignatureFactory class could raise exceptions not declared as thrown by these methods when reading key info or XML signature data from XML input.

A flaw was found in the way the TLS implementation in the JSSE component of OpenJDK re-used single null TLS sessions for new TLS connections. A remote attacker could possibly use this flaw to impact availability of a Java application providing TLS server.

Summary

Log4j versions prior to 2.16.0 are subject to a remote code execution vulnerability via the ldap JNDI parser. As per Apache's Log4j security guide: Apache Log4j2 <=2.14.1 JNDI features used in configuration, log messages, and parameters do not protect against attacker controlled LDAP and other JNDI related endpoints. An attacker who can control log messages or log message parameters can execute arbitrary code loaded from LDAP servers when message lookup substitution is enabled. From log4j 2.16.0, this behavior has been disabled by default.

Log4j version 2.15.0 contained an earlier fix for the vulnerability, but that patch did not disable attacker-controlled JNDI lookups in all situations. For more information, see the Updated advice for version 2.16.0 section of this advisory.

Impact

Logging untrusted or user controlled data with a vulnerable version of Log4J may result in Remote Code Execution (RCE) against your application. This includes untrusted data included in logged errors such as exception traces, authentication failures, and other unexpected vectors of user controlled input.

Affected versions

Any Log4J version prior to v2.15.0 is affected to this specific issue.

The v1 branch of Log4J which is considered End Of Life (EOL) is vulnerable to other RCE vectors so the recommendation is to still update to 2.16.0 where possible.

Security releases Additional backports of this fix have been made available in versions 2.3.1, 2.12.2, and 2.12.3

Affected packages Only the org.apache.logging.log4j:log4j-core package is directly affected by this vulnerability. The org.apache.logging.log4j:log4j-api should be kept at the same version as the org.apache.logging.log4j:log4j-core package to ensure compatability if in use.

Remediation Advice

Updated advice for version 2.16.0

The Apache Logging Services team provided updated mitigation advice upon the release of version 2.16.0, which disables JNDI by default and completely removes support for message lookups. Even in version 2.15.0, lookups used in layouts to provide specific pieces of context information will still recursively resolve, possibly triggering JNDI lookups. This problem is being tracked as CVE-2021-45046. More information is available on the GitHub Security Advisory for CVE-2021-45046.

Users who want to avoid attacker-controlled JNDI lookups but cannot upgrade to 2.16.0 must ensure that no such lookups resolve to attacker-provided data and ensure that the the JndiLookup class is not loaded.

Please note that Log4J v1 is End Of Life (EOL) and will not receive patches for this issue. Log4J v1 is also vulnerable to other RCE vectors and we recommend you migrate to Log4J 2.16.0 where possible.

It was discovered that the XMLEntityManager class implementation in the JAXP component of OpenJDK did not properly perform access checks. A Java application using SAX XML parser in certain configuration could be tricked into disclosing information when parsing a specially-crafted XML file.

A flaw was found in the way the XMLEntityScanner and XML11EntityScanner classes in the JAXP component of OpenJDK handled and normalized newlines in XML entities. A specially-crafted XML document could cause a Java application to enter an infinite loop when parsed.

An integer truncation issue was found in the Xalan Java XSLT library when processing malicious stylesheets. This flaw could be used to potentially execute arbitrary Java bytecode.

In Spring Framework versions 5.3.0 - 5.3.18, 5.2.0 - 5.2.20, and older unsupported versions, the patterns for disallowedFields on a DataBinder are case sensitive which means a field is not effectively protected unless it is listed with both upper and lower case for the first character of the field, including upper and lower case for the first character of all nested fields within the property path.

A flaw was found in Spring Framework. Applications that handle file uploads are vulnerable to a denial of service (DoS) attack if they rely on data binding to set a MultipartFile or javax.servlet.Part to a field in a model object.

Impact

When netty's multipart decoders are used local information disclosure can occur via the local system temporary directory if temporary storing uploads on the disk is enabled.

The CVSSv3.1 score of this vulnerability is calculated to be a 6.2/10

Vulnerability Details

On unix-like systems, the temporary directory is shared between all user. As such, writing to this directory using APIs that do not explicitly set the file/directory permissions can lead to information disclosure. Of note, this does not impact modern MacOS Operating Systems.

The method File.createTempFile on unix-like systems creates a random file, but, by default will create this file with the permissions -rw-r--r--. Thus, if sensitive information is written to this file, other local users can read this information.

This is the case in netty's AbstractDiskHttpData is vulnerable.

https://github.com/netty/netty/blob/e5951d46fc89db507ba7d2968d2ede26378f0b04/codec-http/src/main/java/io/netty/handler/codec/http/multipart/AbstractDiskHttpData.java#L80-L101

AbstractDiskHttpData is used as a part of the DefaultHttpDataFactory class which is used by HttpPostRequestDecoder / HttpPostMultiPartRequestDecoder.

You may be affected by this vulnerability your project contains the following code patterns:

java channelPipeline.addLast(new HttpPostRequestDecoder(...));

java channelPipeline.addLast(new HttpPostMultiPartRequestDecoder(...));

Patches

This has been patched in version 4.1.59.Final.

Workarounds

Specify your own java.io.tmpdir when you start the JVM or use DefaultHttpDataFactory.setBaseDir(...) to set the directory to something that is only readable by the current user.

References

- CWE-378: Creation of Temporary File With Insecure Permissions - CWE-379: Creation of Temporary File in Directory with Insecure Permissions

Similar Vulnerabilities

Similar, but not the same.

- JUnit 4 - https://github.com/junit-team/junit4/security/advisories/GHSA-269g-pwp5-87pp - Google Guava - https://github.com/google/guava/issues/4011 - Apache Ant - https://nvd.nist.gov/vuln/detail/CVE-2020-1945 - JetBrains Kotlin Compiler - https://nvd.nist.gov/vuln/detail/CVE-2020-15824

For more information If you have any questions or comments about this advisory: Open an issue in netty Email us here

Original Report

Hi Netty Security Team, I've been working on some security research leveraging custom CodeQL queries to detect local information disclosure vulnerabilities in java applications. This was the result from running this query against the netty project: https://lgtm.com/query/7723301787255288599/ Netty contains three local information disclosure vulnerabilities, so far as I can tell. One is here, where the private key for the certificate is written to a temporary file. https://github.com/netty/netty/blob/e5951d46fc89db507ba7d2968d2ede26378f0b04/handler/src/main/java/io/netty/handler/ssl/util/SelfSignedCertificate.java#L316-L346 One is here, where the certificate is written to a temporary file. https://github.com/netty/netty/blob/e5951d46fc89db507ba7d2968d2ede26378f0b04/handler/src/main/java/io/netty/handler/ssl/util/SelfSignedCertificate.java#L348-L371 The final one is here, where the 'AbstractDiskHttpData' creates a temporary file if the getBaseDirectory() method returns null. I believe that 'AbstractDiskHttpData' is used as a part of the file upload support? If this is the case, any files uploaded would be similarly vulnerable. https://github.com/netty/netty/blob/e5951d46fc89db507ba7d2968d2ede26378f0b04/codec-http/src/main/java/io/netty/handler/codec/http/multipart/AbstractDiskHttpData.java#L91 All of these vulnerabilities exist because File.createTempFile(String, String) will create a temporary file in the system temporary directory if the 'java.io.tmpdir' system property is not explicitly set. It is my understanding that when java creates a file, by default, and using this method, the permissions on that file utilize the umask. In a majority of cases, this means that the file that java creates has the permissions: -rw-r--r--, thus, any other local user on that system can read the contents of that file. Impacted OS: - Any OS where the system temporary directory is shared between multiple users. This is not the case for MacOS or Windows. Mitigation. Moving to the Files API instead will fix this vulnerability. https://docs.oracle.com/javase/8/docs/api/java/nio/file/Files.html#createTempFile-java.nio.file.Path-java.lang.String-java.lang.String-java.nio.file.attribute.FileAttribute...- This API will explicitly set the posix file permissions to something safe, by default. I recently disclosed a similar vulnerability in JUnit 4: https://github.com/junit-team/junit4/security/advisories/GHSA-269g-pwp5-87pp If you're also curious, this vulnerability in Jetty was also mine, also involving temporary directories, but is not the same vulnerability as in this case. https://github.com/eclipse/jetty.project/security/advisories/GHSA-g3wg-6mcf-8jj6 I would appreciate it if we could perform disclosure of this vulnerability leveraging the GitHub security advisories feature here. GitHub has a nice credit system that I appreciate, plus the disclosures, as you can see from the sampling above, end up looking very nice. https://github.com/netty/netty/security/advisories This vulnerability disclosure follows Google's 90-day vulnerability disclosure policy (I'm not an employee of Google, I just like their policy). Full disclosure will occur either at the end of the 90-day deadline or whenever a patch is made widely available, whichever occurs first. Cheers, Jonathan Leitschuh

A flaw was found in the way the Attributes class in the Libraries component of OpenJDK performed reading of attributes with very long values from JAR file manifests. A specially-crafted JAR archive could cause a Java application reading its manifest to use excessive amount of system resources and hang.

An unspecified vulnerability in Java SE related to the Libraries component could allow an unauthenticated attacker to cause a denial of service resulting in a low availability impact using unknown attack vectors.

An unspecified vulnerability in Java SE related to the Security component could allow an unauthenticated attacker to update, insert or delete data resulting in a low integrity impact using unknown attack vectors.

Vulnerability in the Oracle Java SE, Oracle GraalVM Enterprise Edition product of Oracle Java SE (component: JGSS). Supported versions that are affected are Oracle Java SE: 17.0.4.1, 19; Oracle GraalVM Enterprise Edition: 21.3.3 and 22.2.0. Easily exploitable vulnerability allows unauthenticated attacker with network access via Kerberos to compromise Oracle Java SE, Oracle GraalVM Enterprise Edition. Successful attacks of this vulnerability can result in unauthorized update, insert or delete access to some of Oracle Java SE, Oracle GraalVM Enterprise Edition accessible data. Note: This vulnerability applies to Java deployments, typically in clients running sandboxed Java Web Start applications or sandboxed Java applets, that load and run untrusted code (e.g., code that comes from the internet) and rely on the Java sandbox for security. This vulnerability can also be exploited by using APIs in the specified Component, e.g., through a web service which supplies data to the APIs. CVSS 3.1 Base Score 5.3 (Integrity impacts). CVSS Vector: (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N).

An unspecified vulnerability in Java SE related to the Libraries component could allow an unauthenticated attacker to cause a denial of service resulting in a low availability impact using unknown attack vectors.

A flaw was found in the Pattern class implementation in the Libraries component of OpenJDK. A specially crated input could cause the Pattern class to raise an unexpected exception while performing regular expression matching, possibly causing a Java application using the class to misbehave.

An unspecified vulnerability in Java SE related to the Security component could allow an unauthenticated attacker to update, insert or delete data resulting in a low integrity impact using unknown attack vectors.

An unspecified vulnerability in Java SE related to the Security component could allow an unauthenticated attacker to cause a denial of service resulting in a low availability impact using unknown attack vectors.

A flaw was found in the way the TIFFFaxDecompressor, TIFFLZWDecompressor, and TIFFPackBitsDecompressor classes implementations in the ImageIO component of OpenJDK handled memory allocations when processing TIFF images. A specially-crafted TIFF image with a small size could cause a Java application to allocate an excessive amount of memory when opened.

A flaw was found in the way the Hotspot component of OpenJDK generated class code. An untrusted Java application or applet could potentially use this flaw to bypass Java sandbox restrictions.

It was discovered that the computeNextExponential() method in the Libraries component of OpenJDK failed to comply with the documentation, returning sometimes negative numbers.

A flaw was found in the way the Hotspot component of OpenJDK handled array indexes on 64-bit x86 platform. A large index could trigger a displacement overflow in LIRGenerator::emitarrayaddress, possibly leading to an access at an invalid array position.

A flaw was found in the way the BMPImageReader class implementation in the ImageIO component of OpenJDK preformed memory allocations when reading palette information from BMP images. A specially-crafted BMP file could cause a Java application to consume an excessive amount of memory when opened.