CVE-2005-3899 in Talk
Summary
by MITRE
The automatic update feature in Google Talk allows remote attackers to cause a denial of service (CPU and memory consumption) by poisoning a target s DNS cache and causing a large update file to be sent, which consumes large amounts of CPU and memory during the signature verification, aka BenjiBug.
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Analysis
by VulDB Data Team • 07/30/2017
The vulnerability described in CVE-2005-3899 represents a significant denial of service weakness within Google Talk's automatic update mechanism that leverages DNS cache poisoning techniques to overwhelm target systems. This flaw specifically targets the client-side update process where the application automatically downloads and verifies update files from remote servers. The vulnerability operates through a sophisticated attack vector that combines network-level manipulation with application-level processing inefficiencies.
The technical implementation of this vulnerability exploits the trust model inherent in Google Talk's update system where clients automatically fetch update files without proper validation of the update source. When attackers successfully poison the DNS cache of a target system, they can redirect the update server addresses to malicious hosts that serve large update files. These files are designed to be computationally intensive during signature verification, causing excessive CPU utilization and memory consumption on the victim's system. The attack specifically targets the cryptographic signature verification process that occurs during update installation, where the client must process large amounts of data to validate authenticity.
From an operational impact perspective, this vulnerability enables remote attackers to consume substantial system resources without requiring direct system access or authentication. The attack can be executed from anywhere on the internet and affects any Google Talk client that is configured to automatically download updates. The resource exhaustion manifests as high CPU usage and memory consumption that can render the affected system unusable or significantly degraded, effectively creating a denial of service condition that prevents normal communication and application functionality.
The vulnerability aligns with CWE-400 which describes "Uncontrolled Resource Consumption" and demonstrates characteristics consistent with the ATT&CK technique T1499.004 for "Endpoint Denial of Service" through resource exhaustion. The attack pattern follows the typical methodology of DNS cache poisoning attacks combined with application-level resource consumption, where the attacker leverages legitimate application features to create malicious conditions. This represents a classic case of exploiting trust relationships within software update mechanisms to create security weaknesses.
Mitigation strategies should focus on implementing robust DNS security measures including DNSSEC deployment to prevent cache poisoning attacks, configuring update servers with proper authentication and integrity verification mechanisms, and implementing rate limiting and size restrictions on update downloads. Network-level defenses should include monitoring for unusual update traffic patterns and implementing proper DNS cache validation. Additionally, the application should be configured to perform update verification in a more resource-efficient manner, potentially including pre-verification of update sources and implementation of more efficient signature validation algorithms to prevent the exploitation of this vulnerability.