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Overview

Affected versions of this package are vulnerable to Improper Validation of Integrity Check Value through the integrity check process. An attacker can manipulate the communication by intercepting and dropping specific packets, leading to a compromised connection where security features may be downgraded or disabled (Terrapin attack).

Note:

Both the client and the server implementation must have mitigations applied against this issue, otherwise the connection may still be affected.

Remediation

Upgrade org.apache.sshd:sshd-core to version 2.12.0 or higher.

References

• Apache Advisory
• GitHub Commit
• GitHub Commit
• GitHub Commit
• GitHub Issue
• GitHub PR
• GitHub Release

Overview

Affected versions of this package are vulnerable to Buffer Overflow. It allows an attacker to leverage the SFTP and port forwarding features to overflow the server causing an OutOfMemory error.

Remediation

Upgrade org.apache.sshd:sshd-core to version 2.7.0 or higher.

References

• Apache Mina "Port Forwarding" Documentation
• Apache Mina "SFTP" Documentation
• Apache Security Advisory
• GitHub Commit

Overview

org.bouncycastle:bcprov-jdk15on is a Java implementation of cryptographic algorithms.

Affected versions of this package are vulnerable to Information Exposure. Attackers can obtain sensitive information about a private exponent because of Observable Differences in Behavior to Error Inputs. This occurs in org.bouncycastle.crypto.encodings.OAEPEncoding. Sending invalid ciphertext that decrypts to a short payload in the OAEP Decoder could result in the throwing of an early exception, potentially leaking some information about the private exponent of the RSA private key performing the encryption.

Remediation

Upgrade org.bouncycastle:bcprov-jdk15on to version 1.61 or higher.

References

• GitHub Commit
• Github Wiki

Overview

Affected versions of this package are vulnerable to XML External Entity (XXE) Injection via a crafted HTTP request.

Details

XXE Injection is a type of attack against an application that parses XML input. XML is a markup language that defines a set of rules for encoding documents in a format that is both human-readable and machine-readable. By default, many XML processors allow specification of an external entity, a URI that is dereferenced and evaluated during XML processing. When an XML document is being parsed, the parser can make a request and include the content at the specified URI inside of the XML document.

Attacks can include disclosing local files, which may contain sensitive data such as passwords or private user data, using file: schemes or relative paths in the system identifier.

For example, below is a sample XML document, containing an XML element- username.

<xml>
<?xml version="1.0" encoding="ISO-8859-1"?>
   <username>John</username>
</xml>

An external XML entity - xxe, is defined using a system identifier and present within a DOCTYPE header. These entities can access local or remote content. For example the below code contains an external XML entity that would fetch the content of /etc/passwd and display it to the user rendered by username.

<xml>
<?xml version="1.0" encoding="ISO-8859-1"?>
<!DOCTYPE foo [
   <!ENTITY xxe SYSTEM "file:///etc/passwd" >]>
   <username>&xxe;</username>
</xml>

Other XXE Injection attacks can access local resources that may not stop returning data, possibly impacting application availability and leading to Denial of Service.

Remediation

There is no fixed version for org.jdom:jdom.

References

• GitHub PR
• GitHub Release
• Security Advisory (with PoC)

Overview

org.jdom:jdom2 is a Java manipulation of XML made easy.

Affected versions of this package are vulnerable to XML External Entity (XXE) Injection via a crafted HTTP request.

Details

XXE Injection is a type of attack against an application that parses XML input. XML is a markup language that defines a set of rules for encoding documents in a format that is both human-readable and machine-readable. By default, many XML processors allow specification of an external entity, a URI that is dereferenced and evaluated during XML processing. When an XML document is being parsed, the parser can make a request and include the content at the specified URI inside of the XML document.

Attacks can include disclosing local files, which may contain sensitive data such as passwords or private user data, using file: schemes or relative paths in the system identifier.

For example, below is a sample XML document, containing an XML element- username.

<xml>
<?xml version="1.0" encoding="ISO-8859-1"?>
   <username>John</username>
</xml>

An external XML entity - xxe, is defined using a system identifier and present within a DOCTYPE header. These entities can access local or remote content. For example the below code contains an external XML entity that would fetch the content of /etc/passwd and display it to the user rendered by username.

<xml>
<?xml version="1.0" encoding="ISO-8859-1"?>
<!DOCTYPE foo [
   <!ENTITY xxe SYSTEM "file:///etc/passwd" >]>
   <username>&xxe;</username>
</xml>

Other XXE Injection attacks can access local resources that may not stop returning data, possibly impacting application availability and leading to Denial of Service.

Remediation

Upgrade org.jdom:jdom2 to version 2.0.6.1 or higher.

References

• GitHub PR
• GitHub Release
• Security Advisory (with PoC)

Overview

xerces:xercesImpl is a that is used for high performance, fully compliant XML parsers in the Apache Xerces family.

Affected versions of this package are vulnerable to Denial of Service (DoS) via the XML parser when handling specially crafted XML document payloads. When the parser tries to parse such a document it gets stuck in an infinite loop for a long time, which consumes resources.

Details

Denial of Service (DoS) describes a family of attacks, all aimed at making a system inaccessible to its intended and legitimate users.

Unlike other vulnerabilities, DoS attacks usually do not aim at breaching security. Rather, they are focused on making websites and services unavailable to genuine users resulting in downtime.

One popular Denial of Service vulnerability is DDoS (a Distributed Denial of Service), an attack that attempts to clog network pipes to the system by generating a large volume of traffic from many machines.

When it comes to open source libraries, DoS vulnerabilities allow attackers to trigger such a crash or crippling of the service by using a flaw either in the application code or from the use of open source libraries.

Two common types of DoS vulnerabilities:

• High CPU/Memory Consumption- An attacker sending crafted requests that could cause the system to take a disproportionate amount of time to process. For example, commons-fileupload:commons-fileupload.

• Crash - An attacker sending crafted requests that could cause the system to crash. For Example, npm ws package

Remediation

Upgrade xerces:xercesImpl to version 2.12.2 or higher.

References

• Apache Pony Mail
• Fix Revision
• MarkMail
• Release Notes

AGPL-3.0 license