CVE-2020-4767 in Sterling Connect Direct
Summary
by MITRE • 10/28/2020
IBM Sterling Connect Direct for Microsoft Windows 4.7, 4.8, 6.0, and 6.1 could allow a remote attacker to cause a denial of service, caused by a buffer over-read. Bysending a specially crafted request, the attacker could cause the application to crash. IBM X-Force ID: 188906.
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Analysis
by VulDB Data Team • 11/30/2020
IBM Sterling Connect Direct for Microsoft Windows versions 4.7, 4.8, 6.0, and 6.1 contains a critical buffer over-read vulnerability that enables remote attackers to execute denial of service attacks. This flaw resides in the application's handling of specially crafted network requests that exceed allocated buffer boundaries, leading to memory access violations and subsequent application crashes. The vulnerability manifests when the system processes malformed input data without proper bounds checking, allowing an attacker to manipulate memory structures and cause the service to terminate unexpectedly. This issue represents a classic buffer over-read condition classified under CWE-125, where an application reads memory beyond the boundaries of a allocated buffer, potentially exposing sensitive data or causing system instability. The attack vector requires remote network access to the affected system, making it particularly dangerous in enterprise environments where connectivity is extensive. From an operational perspective, this vulnerability directly impacts the availability of critical file transfer services that organizations rely upon for business continuity. The denial of service condition can disrupt automated file transfer processes, impact business operations, and potentially cause cascading failures in dependent systems that depend on Sterling Connect Direct for Windows functionality. The vulnerability's impact is amplified by the fact that it affects multiple versions of the software, suggesting a widespread exposure across various organizational deployments. Attackers can exploit this weakness by crafting malicious requests that trigger the buffer over-read condition, causing the application to crash and potentially requiring system restarts to restore normal operations. The IBM X-Force ID 188906 associated with this vulnerability indicates that security researchers have documented and analyzed the specific exploitation techniques that can be employed against this flaw. Organizations utilizing these versions of Sterling Connect Direct should consider the vulnerability's potential for causing significant operational disruption, particularly in mission-critical environments where continuous availability is essential. The flaw aligns with ATT&CK technique T1499.004, which involves network denial of service attacks, and represents a direct threat to system availability and service integrity within enterprise networks.
The technical implementation of this vulnerability demonstrates poor input validation and memory management practices within the application's network processing components. When legitimate requests are processed, the system fails to validate the size or structure of incoming data against predefined buffer limits, allowing malicious inputs to overflow allocated memory regions. This over-read condition can result in unpredictable behavior including crashes, data corruption, or potentially even information disclosure if the overflowed memory contains sensitive data. The vulnerability's exploitation requires minimal technical expertise and can be automated, making it attractive to threat actors seeking to disrupt services without requiring sophisticated attack capabilities. System administrators should note that this vulnerability affects the core functionality of the file transfer service, meaning that successful exploitation can prevent legitimate file transfers from occurring, potentially causing operational delays or complete service outages. The lack of proper bounds checking in the application's request handling routines indicates a fundamental security weakness that could be indicative of broader architectural issues within the software's design. Organizations should prioritize patching or implementing workarounds for this vulnerability, as the potential for exploitation exists in environments where the affected software is exposed to untrusted network traffic. The vulnerability's classification as a remote denial of service means that attackers do not need physical access to the system or elevated privileges to cause disruption, making it particularly concerning for organizations with exposed services or those operating in hostile network environments. The impact extends beyond simple service interruption, as file transfer operations often form critical components of business processes, and disruptions can have cascading effects throughout enterprise infrastructure.