CVE-2005-3678 in Talk
Summary
by MITRE
Google Talk before 1.0.0.76, with email notification enabled, allows remote attackers to cause a denial of service (connection reset) via email with a blank sender.
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Analysis
by VulDB Data Team • 07/13/2018
The vulnerability described in CVE-2005-3678 represents a denial of service weakness in Google Talk client software prior to version 1.0.0.76. This issue specifically manifests when the email notification feature is enabled within the application, creating a condition where remote attackers can exploit the system by sending specially crafted email messages containing blank sender addresses. The flaw operates at the protocol level where the client application fails to properly handle malformed email headers, particularly those lacking valid sender information.
The technical implementation of this vulnerability stems from insufficient input validation within the email processing module of the Google Talk client. When the application receives an email message with a blank or null sender field, it does not implement proper error handling mechanisms to gracefully manage this edge case. Instead, the client attempts to process the malformed message and subsequently terminates the connection to the messaging server, resulting in a service disruption for legitimate users. This behavior aligns with CWE-20, which addresses improper input validation, and demonstrates how inadequate sanitization of user-supplied data can lead to system instability.
The operational impact of this vulnerability extends beyond simple service disruption as it can be exploited by malicious actors to systematically degrade the availability of Google Talk services. Attackers can repeatedly send emails with blank sender fields to multiple users or servers, causing cascading connection resets that effectively render the messaging service unusable. This type of attack maps to the ATT&CK technique T1499.004, which covers network denial of service attacks, and represents a classic example of how seemingly benign protocol features can become attack vectors when proper validation mechanisms are absent. The vulnerability affects the core communication reliability of the application and can be particularly disruptive in environments where continuous messaging availability is critical.
Mitigation strategies for this vulnerability include immediate deployment of the patched Google Talk client version 1.0.0.76 or later, which implements proper validation for email sender fields. Organizations should also consider implementing email filtering rules that can identify and block messages with malformed headers before they reach the vulnerable client applications. Network administrators can deploy intrusion prevention systems that monitor for patterns consistent with this specific attack vector, although such measures are less effective than client-side patching. The incident highlights the importance of robust input validation and proper error handling in communication protocols, particularly for applications that process external data streams. Security teams should also consider implementing monitoring for abnormal connection termination patterns that could indicate exploitation of similar input validation vulnerabilities.