CVE-2008-5421 in SmsGate
Summary
by MITRE
The SSL web administration service in NetWin SmsGate 1.1n and earlier allows remote attackers to cause a denial of service (hang) via (1) a large integer in the Content-Length HTTP header; (2) an invalid value in the Content-Length HTTP header, as demonstrated by a negative integer; or (3) a missing Content-Length HTTP header.
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Analysis
by VulDB Data Team • 10/21/2018
The vulnerability identified as CVE-2008-5421 affects the SSL web administration service component of NetWin SmsGate version 1.1n and earlier systems. This represents a critical denial of service weakness that can be exploited by remote attackers to disrupt the availability of the affected service. The vulnerability specifically targets the HTTP protocol handling mechanism within the web administration interface, which is designed to manage the secure communication channel for system administration tasks. The affected service operates over SSL/TLS encryption, making it particularly concerning as it could potentially impact administrative access to the SMS gateway infrastructure.
The technical flaw manifests through improper validation of HTTP Content-Length header values during request processing. When the web administration service receives HTTP requests with malformed Content-Length headers, it fails to properly handle these invalid inputs, leading to system hang conditions. The vulnerability can be triggered through three distinct attack vectors including the submission of excessively large integer values in the Content-Length header that exceed system processing capabilities, the introduction of negative integer values that cause arithmetic overflow or invalid state conditions, or the complete omission of the Content-Length header altogether. Each of these scenarios demonstrates a lack of proper input sanitization and validation mechanisms within the HTTP request parsing logic of the service.
From an operational impact perspective, this vulnerability presents a significant threat to the availability and reliability of the NetWin SmsGate administration interface. When successfully exploited, the service becomes unresponsive and enters a hung state, effectively preventing legitimate administrators from accessing critical system configuration and monitoring functions. This denial of service condition can persist until the affected service is manually restarted or the system is rebooted, creating potential downtime for SMS gateway operations that may impact communication services. The remote nature of the attack means that adversaries can exploit this weakness without requiring physical access or authentication credentials, making it particularly dangerous in production environments where administrative access is crucial for system maintenance and security operations.
The vulnerability aligns with CWE-129, which describes improper validation of input ranges, and CWE-191, which addresses integer underflow and overflow conditions. Additionally, this weakness maps to ATT&CK technique T1499.004, which covers network denial of service attacks, and T1566.001, which involves social engineering through spearphishing. Organizations should implement immediate mitigations including input validation for HTTP headers, implementing rate limiting mechanisms, and configuring proper timeouts for HTTP request processing. System administrators should also consider applying the vendor-provided patch or upgrading to a newer version of the NetWin SmsGate software that addresses these input validation issues. Network segmentation and monitoring solutions should be deployed to detect anomalous HTTP header patterns that may indicate exploitation attempts, while access controls should be enforced to limit exposure of the administration interface to trusted networks only.