CVE-2010-1689 in Windows
Summary
by MITRE
The DNS implementation in smtpsvc.dll before 6.0.2600.5949 in Microsoft Windows 2000 SP4 and earlier, Windows XP SP3 and earlier, Windows Server 2003 SP2 and earlier, Windows Server 2008 SP2 and earlier, Windows Server 2008 R2, Exchange Server 2003 SP3 and earlier, Exchange Server 2007 SP2 and earlier, and Exchange Server 2010 uses predictable transaction IDs that are formed by incrementing a previous ID by 1, which makes it easier for man-in-the-middle attackers to spoof DNS responses, a different vulnerability than CVE-2010-0024 and CVE-2010-0025.
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Analysis
by VulDB Data Team • 09/13/2021
The vulnerability described in CVE-2010-1689 represents a critical weakness in the Domain Name System (DNS) resolution mechanism implemented within Microsoft's Simple Mail Transfer Protocol (SMTP) service component. This flaw affects a broad range of Microsoft operating systems and server products including Windows 2000 through Windows Server 2008 R2, along with various Exchange Server versions. The issue stems from the predictable nature of transaction identifiers used in DNS queries, which creates significant security implications for network communications. The smtpsvc.dll module, which handles SMTP functionality in these systems, generates transaction IDs using a sequential incrementing algorithm that follows a simple mathematical progression, making it trivial for malicious actors to predict future transaction identifiers.
The technical implementation of this vulnerability involves the DNS transaction ID generation process within Microsoft's SMTP service where the system employs a predictable sequence rather than cryptographically secure random number generation. When the DNS resolver sends a query to a DNS server, it includes a transaction ID that serves as a correlation mechanism between the query and its response. In vulnerable systems, this transaction ID is incremented by one from the previous value, creating a pattern that can be easily anticipated. This predictable sequence allows attackers positioned in man-in-the-middle positions to monitor DNS traffic and use the knowledge of the next expected transaction ID to inject false DNS responses into the communication stream. The vulnerability specifically affects the DNS resolution process within the SMTP service, which is critical for email delivery operations and can be exploited to redirect email traffic to malicious servers or to intercept communications.
The operational impact of this vulnerability extends beyond simple DNS spoofing attacks and can severely compromise the integrity of email communications within affected networks. Attackers can leverage this weakness to redirect email traffic to compromised servers, potentially leading to data interception, man-in-the-middle attacks, or unauthorized access to email systems. The vulnerability creates opportunities for attackers to compromise email infrastructure by exploiting the predictable transaction ID sequence, which can result in unauthorized access to sensitive email communications, potential data breaches, and disruption of email services. Network administrators face significant challenges in defending against such attacks since the vulnerability lies within the core DNS resolution mechanism of the SMTP service, making it difficult to implement targeted patches without affecting email functionality. The impact is particularly severe in enterprise environments where email systems form the backbone of business communications and where the compromise of email infrastructure can lead to widespread operational disruption.
Mitigation strategies for this vulnerability require immediate implementation of security updates provided by Microsoft to address the predictable transaction ID generation issue in the smtpsvc.dll component. Organizations should prioritize patching affected systems with the relevant security updates released by Microsoft, which address the specific DNS transaction ID generation flaw. Network administrators should also consider implementing additional security controls such as DNSSEC deployment to provide cryptographic authentication of DNS responses, which can help protect against spoofing attacks even when the underlying vulnerability exists. The implementation of proper network segmentation and monitoring solutions can help detect anomalous DNS traffic patterns that might indicate exploitation attempts. Additionally, organizations should conduct comprehensive vulnerability assessments to identify all systems running affected versions of Microsoft Windows and Exchange Server, ensuring that all endpoints are properly updated and secured. This vulnerability aligns with CWE-338, which addresses the use of cryptographically weak pseudo-random number generators, and represents a clear violation of security best practices regarding predictable sequence generation in network protocols. The attack vectors associated with this vulnerability map to ATT&CK techniques involving DNS tunneling and man-in-the-middle attacks, emphasizing the need for layered defense mechanisms to protect against such threats.