Netscape Navigator/Communicator URL Buffer Overflow
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.
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.
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.
Configure network firewalls to block access to untrusted or suspicious websites, particularly those with unusually long URL parameters, to prevent malicious traffic from reaching vulnerable clients. Deploy intrusion detection systems (IDS) to monitor network traffic for exploit attempts targeting long URL strings in HTTP requests. Additionally, educate users to avoid clicking unknown links or visiting suspicious websites to reduce the likelihood of exploitation.
The permanent resolution is to upgrade Netscape Navigator/Communicator to a version where this specific buffer overflow vulnerability has been patched. This vulnerability specifically affects Netscape Navigator/Communicator 4.7 running on Windows 95 and Windows 98. Users should consider migrating to modern, supported web browsers, as these legacy versions are extremely outdated and have numerous unpatched security flaws.
An attacker can exploit this buffer overflow by crafting a malicious URL with a long argument, causing a denial of service that crashes Netscape Navigator/Communicator. Depending on the attack vector, arbitrary command execution might also be possible, leading to full system compromise, data theft, or further network penetration. This could result in significant operational disruption and security breaches.
No CWE classification has been assigned.
Other CVEs affecting communicator
Apache Log4j2 2.0-beta9 through 2.15.0 (excluding security releases 2.12.2, 2.12.3, and 2.3.1) 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 2.15.0, this behavior has been disabled by default. From version 2.16.0 (along with 2.12.2, 2.12.3, and 2.3.1), this functionality has been completely removed. Note that this vulnerability is specific to log4j-core and does not affect log4net, log4cxx, or other Apache Logging Services projects.
It was found that the fix to address CVE-2021-44228 in Apache Log4j 2.15.0 was incomplete in certain non-default configurations. This could allows attackers with control over Thread Context Map (MDC) input data when the logging configuration uses a non-default Pattern Layout with either a Context Lookup (for example, $${ctx:loginId}) or a Thread Context Map pattern (%X, %mdc, or %MDC) to craft malicious input data using a JNDI Lookup pattern resulting in an information leak and remote code execution in some environments and local code execution in all environments. Log4j 2.16.0 (Java 8) and 2.12.2 (Java 7) fix this issue by removing support for message lookup patterns and disabling JNDI functionality by default.
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.
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.
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.