Source: cve@mitre.org
Java Runtime Environment (JRE) and SDK 1.2 through 1.3.0_04 allows untrusted applets to access the system clipboard.
Java Runtime Environment (JRE) and SDK versions 1.2 through 1.3.0_04 are vulnerable to a critical security flaw allowing malicious applets to access and exfiltrate sensitive data stored in the system clipboard. This vulnerability enables attackers to steal confidential information copied by users, potentially leading to data breaches and unauthorized access to sensitive systems.
Step 1: Payload Delivery: The attacker crafts a malicious Java applet, typically hosted on a compromised website or delivered via social engineering (e.g., phishing).
Step 2: User Interaction: The victim visits the malicious website or opens an email containing the applet. The applet is automatically executed by the vulnerable JRE.
Step 3: Clipboard Access: The malicious applet uses Java's clipboard API (e.g., java.awt.datatransfer) to read the contents of the system clipboard.
Step 4: Data Exfiltration: The applet then transmits the stolen clipboard data to a remote server controlled by the attacker. This could be done through various methods, such as HTTP POST requests or DNS tunneling.
The vulnerability stems from a lack of proper access control within the Java security sandbox for clipboard operations. Specifically, the JRE and SDK versions in question failed to adequately restrict applets from reading and writing to the system clipboard. The root cause is likely a flaw in the security manager's implementation, which did not correctly validate the origin and permissions of applets attempting to interact with the clipboard. This allowed untrusted applets to bypass security checks and access the clipboard contents without user consent. The lack of proper validation allowed an attacker to create a malicious applet that could read the clipboard contents, potentially including sensitive data like passwords, credit card numbers, or other confidential information. The vulnerability is a classic example of a privilege escalation issue, where a low-privilege context (the applet) gains unauthorized access to a higher-privilege resource (the system clipboard).
Due to the age of the vulnerability, specific APT groups are not directly linked to its exploitation. However, any threat actor targeting legacy systems or organizations that haven't updated their Java installations could potentially leverage this vulnerability. The vulnerability is not listed in the CISA KEV database, reflecting its age and the fact that it is not considered a high-priority threat in the current threat landscape.
Monitor network traffic for unusual outbound connections from systems running vulnerable Java versions, especially those originating from web browsers.
Analyze web server logs for requests to serve Java applets from suspicious or compromised domains.
Inspect system clipboard contents for sensitive data using forensic tools, especially on systems known to have accessed potentially malicious websites.
Monitor for the execution of Java applets from untrusted sources using endpoint detection and response (EDR) solutions.
Review Java security logs for suspicious clipboard access attempts.
Upgrade to a patched version of the Java Runtime Environment (JRE) or SDK. This is the most effective mitigation strategy. Ensure that all systems are running a supported and up-to-date version of Java.
Disable Java in web browsers if it is not required. This reduces the attack surface by preventing the execution of Java applets.
Implement a web application firewall (WAF) to block access to malicious websites that may host exploit code.
Educate users about the risks of visiting untrusted websites and opening suspicious emails. Train users to avoid clicking on links or downloading files from unknown sources.
Regularly scan systems for vulnerable Java installations using vulnerability scanners.