Netscape Communicator Malicious Applet Server Creation
Severe, but no confirmed exploitation yet. Schedule remediation in your next patch cycle and apply mitigations if you're exposed.
An unauthenticated attacker, remotely over the network, can cause limited impact to confidentiality and integrity and availability.
Netscape Communicator does not properly prevent a ServerSocket object from being created by untrusted entities, which allows remote attackers to create a server on the victim's system via a malicious applet, as demonstrated by Brown Orifice.
Inferred from the weakness type (CWE) and how the flaw is reached — the techniques an attacker would chain to exploit this. Real-world corroboration appears here as threat intel is folded in.
Generated by Wavense from the CVE record — an immediate mitigation and the permanent fix.
As an interim measure, disable Java applets in Netscape Communicator's security settings if their functionality is not absolutely critical for business operations. Implement network egress filtering at the firewall level to block unauthorized outbound connections from client workstations, which could help detect or prevent the server created by an attacker from communicating externally. Additionally, deploy endpoint detection and response (EDR) solutions to monitor for unusual process activity or unauthorized network listening ports on systems running Netscape Communicator.
The permanent resolution requires upgrading Netscape Communicator to a version that has patched the ServerSocket object vulnerability. Users should consult official Netscape or AOL security advisories for specific patch releases and upgrade paths. If an official patch is no longer available due to the age of the software, consider migrating to a modern, supported web browser with robust security features to eliminate this and other known vulnerabilities.
A remote attacker can exploit this flaw by delivering a malicious applet, enabling them to create an unauthorized server on the victim's system. This could grant the attacker remote access to the victim's machine, allowing for data exfiltration, further malware deployment, or using the compromised system for malicious network activities. The consequences include potential data breaches, unauthorized system control, and a significant loss of confidentiality and integrity.
No CWE classification has been assigned.
Other CVEs affecting virtual machine
Microsoft Virtual Machine (VM) allows remote attackers to escape the Java sandbox and execute commands via an applet containing an illegal cast operation, aka the "Virtual Machine Verifier" vulnerability.
Netscape Communicator before 4.77 allows remote attackers to execute arbitrary Javascript via a GIF image whose comment contains the Javascript.
Buffer overflow in the HTML parser for Netscape 4.75 and earlier allows remote attackers to execute arbitrary commands via a long password value in a form field.
Buffer overflow in Netscape Navigator/Communicator 4.7 for Windows 95 and Windows 98 allows remote attackers to cause a denial of service, and possibly execute arbitrary commands, via a long argument after the ? character in a URL that references an .asp, .cgi, .html, or .pl file.
Netscape Communicator 4.04 through 4.7 (and possibly other versions) in various UNIX operating systems converts the 0x8b character to a "<" sign, and the 0x9b character to a ">" sign, which could allow remote attackers to attack other clients via cross-site scripting (CSS) in CGI programs that do not filter these characters.
The byte code verifier component of the Java Virtual Machine (JVM) allows remote execution through malicious web pages.