CVE-2010-1100 in Arora
Summary
by MITRE
Integer overflow in Arora allows remote attackers to bypass intended port restrictions on outbound TCP connections via a port number outside the range of the unsigned short data type, as demonstrated by a value of 65561 for TCP port 25.
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Analysis
by VulDB Data Team • 05/03/2026
The vulnerability identified as CVE-2010-1100 represents a critical integer overflow flaw within the Arora web browser implementation that fundamentally compromises network security controls. This issue specifically affects the handling of TCP port numbers during outbound connection attempts, creating a pathway for malicious actors to circumvent established security boundaries. The vulnerability manifests when the browser processes port numbers that exceed the maximum value representable by an unsigned short data type, which is 65535, thereby enabling attackers to manipulate connection parameters beyond normal operational limits.
The technical exploitation of this vulnerability relies on the improper validation of port numbers within the network stack implementation of Arora. When a port value of 65561 is specified for TCP port 25, the system fails to properly handle the overflow condition, allowing the application to interpret this value as a valid connection target. This occurs because the unsigned short data type can only accommodate values up to 65535, yet the application does not implement adequate bounds checking or overflow protection mechanisms. The flaw essentially creates a scenario where the integer arithmetic produces unexpected results that bypass intended security restrictions, particularly those governing outbound TCP connections to commonly restricted ports.
The operational impact of this vulnerability extends beyond simple port bypassing, as it enables attackers to establish connections to ports that should normally be restricted or blocked by firewall rules and network policies. This capability allows for potential exploitation of services that typically operate on ports outside the standard range, enabling malicious actors to probe network infrastructure, establish unauthorized communication channels, or bypass network security controls. The vulnerability particularly affects email servers and other network services that rely on specific port restrictions for security purposes, as the attacker can effectively force connections through ports that would normally be blocked or monitored.
This vulnerability maps directly to CWE-190, which describes integer overflow conditions that can lead to unexpected behavior in applications. The flaw also aligns with ATT&CK technique T1071.004, which covers application layer protocol: DNS, demonstrating how network protocol implementations can be manipulated to bypass security controls. The security implications are particularly severe in environments where network segmentation and port-based access controls are critical components of the overall security posture. Organizations relying on Arora for web browsing activities face significant risk, as this vulnerability could be exploited to gain unauthorized access to internal network resources or to conduct reconnaissance activities that would otherwise be prevented by standard port filtering mechanisms.
The recommended mitigations for this vulnerability include immediate application of vendor patches or updates that address the integer overflow in port handling logic, implementation of additional input validation at the network stack level, and deployment of network monitoring solutions that can detect anomalous port connection patterns. System administrators should also consider implementing more robust firewall rules that explicitly block connections to ports outside expected ranges and establish network segmentation controls that limit the impact of such vulnerabilities. Additionally, organizations should conduct comprehensive vulnerability assessments to identify similar integer overflow conditions in other network applications and systems that may be susceptible to analogous attacks, as this type of flaw often indicates broader architectural weaknesses in input validation and boundary checking mechanisms.