CVE-2007-0672 in Mobile Backup
Summary
by MITRE
LGSERVER.EXE in BrightStor Mobile Backup 4.0 allows remote attackers to cause a denial of service (disk consumption and daemon hang) via a value of 0xFFFFFF7F at a certain point in an authentication negotiation packet, which writes a large amount of data to a .USX file in CA_BABLDdata\Server\data\transfer\.
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Analysis
by VulDB Data Team • 07/13/2021
The vulnerability identified as CVE-2007-0672 resides within LGSERVER.EXE component of BrightStor Mobile Backup 4.0, representing a critical denial of service weakness that enables remote attackers to compromise system availability. This flaw manifests during the authentication negotiation process when a specially crafted value of 0xFFFFFF7F is transmitted, triggering abnormal behavior that consumes excessive system resources and ultimately leads to daemon hanging. The vulnerability operates at the network protocol level where authentication packets are processed, making it particularly dangerous as it can be exploited without requiring authentication credentials or local access to the system.
The technical exploitation of this vulnerability involves sending a malformed authentication negotiation packet containing the specific value 0xFFFFFF7F at a designated position within the communication stream. When the LGSERVER.EXE process encounters this value, it triggers an unintended code path that results in excessive disk I/O operations. The system begins writing substantial amounts of data to a .USX file located within the CA_BABLDdata\Server\data\ransfer\ directory structure, causing rapid disk space exhaustion and system resource depletion. This particular value represents a negative integer that, when interpreted by the vulnerable software, causes integer overflow or underflow conditions leading to uncontrolled memory allocation and file writing operations.
The operational impact of this vulnerability extends beyond simple service disruption, creating cascading effects that can compromise entire backup operations and potentially lead to system instability. The disk consumption aspect of this vulnerability can quickly fill available storage space, preventing legitimate backup operations from completing successfully and potentially causing system crashes or severe performance degradation. The daemon hanging characteristic means that the backup service becomes unresponsive and requires manual intervention to restore functionality, resulting in extended downtime and potential data loss scenarios. Organizations relying on BrightStor Mobile Backup for critical data protection may face significant operational disruptions when this vulnerability is exploited.
Security professionals should recognize this vulnerability as a classic example of improper input validation and resource management, falling under CWE-129 Input Validation and CWE-770 Allocation of Resources Without Limits or Throttling. The attack pattern aligns with ATT&CK technique T1499.004 for Network Denial of Service, where adversaries exploit software weaknesses to consume system resources and render services unavailable. Mitigation strategies should focus on implementing network segmentation to limit exposure, applying vendor-provided patches or updates, and monitoring for unusual disk I/O patterns or authentication negotiation anomalies. Organizations should also consider implementing intrusion detection systems to identify and block malicious packets containing the specific triggering value 0xFFFFFF7F, while establishing automated alerts for disk space exhaustion and daemon hang conditions to enable rapid response to potential exploitation attempts.