CVE-2006-5179 in iGateway SSL-VPN
Summary
by MITRE
Intoto iGateway VPN and iGateway SSL-VPN allow context-dependent attackers to cause a denial of service (CPU consumption) via parasitic public keys with large (1) "public exponent" or (2) "public modulus" values in X.509 certificates that require extra time to process when using RSA signature verification, a related issue to CVE-2006-2940.
If you want to get the best quality for vulnerability data then you always have to consider VulDB.
Analysis
by VulDB Data Team • 04/23/2026
The vulnerability described in CVE-2006-5179 affects the intoto iGateway VPN and iGateway SSL-VPN products, representing a significant security concern that exploits weaknesses in RSA signature verification processes. This issue specifically targets the handling of X.509 certificates containing public keys with unusually large public exponents or public modulus values, creating a scenario where legitimate certificate validation operations consume excessive computational resources. The vulnerability operates through a context-dependent attack vector where adversaries can manipulate certificate parameters to force the system into performing computationally expensive operations during signature verification processes.
The technical flaw stems from the cryptographic implementation's lack of proper parameter validation when processing RSA public keys within X.509 certificates. When the system encounters certificates with large public exponents or large public modulus values, the RSA verification algorithm requires significantly more processing time to complete the mathematical operations. This occurs because the RSA algorithm's computational complexity increases substantially with the size of these parameters, particularly when the public exponent exceeds normal ranges or when the modulus contains an excessive number of bits. The vulnerability represents a classic example of a resource exhaustion attack that leverages mathematical properties rather than traditional exploitation techniques.
The operational impact of this vulnerability manifests as a denial of service condition where the affected VPN systems experience excessive CPU consumption, potentially leading to complete system unavailability. Attackers can exploit this weakness by presenting specially crafted certificates that contain parasitic public keys with oversized parameters, causing the system to spend considerable time performing signature verification operations. This resource consumption can be sustained over time, creating a persistent denial of service condition that affects legitimate users attempting to establish secure connections through the VPN infrastructure. The attack becomes particularly dangerous in high-traffic environments where multiple concurrent connections could amplify the impact.
From a cybersecurity perspective, this vulnerability aligns with CWE-1321, which addresses issues related to cryptographic weaknesses in parameter validation, and demonstrates characteristics consistent with attack patterns found in the ATT&CK framework under the privilege escalation and denial of service domains. The vulnerability's relationship to CVE-2006-2940 indicates a broader class of cryptographic weaknesses affecting similar systems, suggesting that organizations implementing RSA-based security solutions should consider comprehensive cryptographic parameter validation mechanisms. Mitigation strategies should focus on implementing certificate validation policies that reject certificates with suspicious parameter sizes, deploying rate limiting mechanisms to prevent abuse, and ensuring that cryptographic libraries are properly configured to handle edge cases in public key parameters. Organizations should also consider implementing monitoring systems that can detect unusual CPU consumption patterns that may indicate exploitation attempts.