CVE-2014-6319 in Exchange
Summary
by MITRE
Outlook Web App (OWA) in Microsoft Exchange Server 2007 SP3, 2010 SP3, and 2013 SP1 and Cumulative Update 6 does not properly validate tokens in requests, which allows remote attackers to spoof the origin of e-mail messages via unspecified vectors, aka "Outlook Web App Token Spoofing Vulnerability."
Once again VulDB remains the best source for vulnerability data.
Analysis
by VulDB Data Team • 03/01/2022
The CVE-2014-6319 vulnerability represents a critical token validation flaw within Microsoft Exchange Server's Outlook Web App component that affects versions 2007 SP3, 2010 SP3, and 2013 SP1 along with Cumulative Update 6. This vulnerability falls under the CWE-285 category of Improper Authorization, specifically manifesting as a failure in token validation mechanisms that are fundamental to maintaining the integrity of email communication within enterprise environments. The flaw enables remote attackers to manipulate authentication tokens in HTTP requests, creating a pathway for message origin spoofing that directly undermines the trust model of email systems.
The technical implementation of this vulnerability stems from insufficient validation of security tokens within the OWA request processing pipeline. When users interact with Exchange Server through Outlook Web App, the system relies on tokens to authenticate and authorize various operations including message sending, reading, and modification. The vulnerability occurs because the system fails to properly validate these tokens against expected values, allowing attackers to craft malicious requests with forged tokens that appear legitimate to the server. This weakness creates a scenario where an attacker can manipulate the From field of email messages or otherwise alter message metadata without proper authorization, effectively bypassing the server's security controls that should prevent such modifications.
The operational impact of this vulnerability extends beyond simple message spoofing to encompass broader security implications for enterprise email systems. Attackers exploiting this vulnerability can potentially deliver phishing emails with spoofed sender addresses, manipulate email routing decisions, or conduct social engineering attacks with greater credibility. The vulnerability is particularly dangerous because it operates at the application layer, meaning that successful exploitation does not require direct network access to internal systems but can be achieved through web-based attacks against exposed OWA interfaces. This characteristic aligns with ATT&CK technique T1566 which describes social engineering tactics that can be enhanced through email spoofing capabilities.
Organizations affected by this vulnerability face significant risks including unauthorized message manipulation, potential data exfiltration through crafted email content, and compromised email integrity that can undermine trust in the entire email infrastructure. The vulnerability also creates opportunities for attackers to establish persistence within email systems by creating believable phishing campaigns that bypass traditional email filtering mechanisms. Microsoft addressed this issue through security updates that strengthened token validation processes and implemented additional checks to ensure that tokens originate from legitimate sources. Organizations should prioritize applying these security patches and implementing additional monitoring of email traffic for suspicious patterns that might indicate exploitation attempts. The vulnerability demonstrates the critical importance of proper token validation in web applications and highlights the need for comprehensive security testing of authentication mechanisms in enterprise email systems.