CVE-2007-0673 in ARCserve Backup
Summary
by MITRE
LGSERVER.EXE in BrightStor ARCserve Backup for Laptops & Desktops r11.1 allows remote attackers to cause a denial of service (daemon crash) via a value of 0xFFFFFFFF at a certain point in an authentication negotiation packet, which results in an out-of-bounds read.
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Analysis
by VulDB Data Team • 07/14/2019
The vulnerability identified as CVE-2007-0673 affects LGSERVER.EXE component within BrightStor ARCserve Backup for Laptops & Desktops version r11.1, representing a critical security flaw that enables remote attackers to execute denial of service attacks against the backup daemon. This vulnerability specifically targets the authentication negotiation process where the daemon fails to properly validate incoming packet values, creating an exploitable condition that can crash the entire backup service. The flaw manifests when the authentication negotiation packet contains a value of 0xFFFFFFFF at a particular position, triggering an out-of-bounds memory read operation that ultimately leads to daemon termination.
The technical implementation of this vulnerability stems from inadequate input validation within the LGSERVER.EXE process, which operates under the Common Weakness Enumeration framework as CWE-125, specifically addressing out-of-bounds read conditions. The daemon processes authentication packets without proper bounds checking on integer values, allowing malicious actors to craft specially formatted packets that contain the invalid 0xFFFFFFFF value. This particular value triggers a memory access violation when the daemon attempts to interpret the packet data, as the system fails to validate that the received value falls within acceptable parameter ranges before proceeding with memory operations. The vulnerability represents a classic example of insufficient boundary checking, where the authentication protocol implementation does not account for edge cases in value processing.
The operational impact of this vulnerability extends beyond simple service disruption, as it can severely compromise backup operations for desktop and laptop systems that rely on BrightStor ARCserve Backup. When the daemon crashes, all ongoing backup operations cease immediately, potentially leaving systems in an unprotected state where critical data cannot be backed up or restored. Network administrators and security personnel face the challenge of maintaining backup integrity while the service remains vulnerable, as the crash occurs during the authentication phase, meaning legitimate users may be unable to establish connections to the backup service. This vulnerability is particularly concerning in enterprise environments where backup systems are critical infrastructure components, as it can result in extended downtime for backup operations and potential data loss scenarios.
Mitigation strategies for CVE-2007-0673 should focus on immediate patch deployment from the vendor, as the vulnerability affects a core authentication component that provides remote attack surface. Organizations should implement network segmentation to limit access to the affected backup service, reducing the potential attack surface for remote exploitation. The implementation of input validation controls and boundary checking mechanisms should be enforced at the application level, with proper error handling procedures that prevent malformed packets from causing daemon crashes. Additionally, monitoring systems should be configured to detect unusual authentication packet patterns that may indicate exploitation attempts, and regular security audits should verify that authentication protocols properly validate all incoming data. From an ATT&CK framework perspective, this vulnerability maps to T1499.004 (Endpoint Denial of Service) and T1566.001 (Phishing), as attackers may use social engineering to gain initial access before exploiting this authentication bypass vulnerability. The vulnerability also aligns with T1071.004 (Application Layer Protocol: DNS) in scenarios where attackers might leverage DNS-based attacks to reach the backup service.