CVE-2013-4677 in Backup Exec
Summary
by MITRE
Symantec Backup Exec 2010 R3 before 2010 R3 SP3 and 2012 before SP2 uses weak permissions (Everyone: Read and Everyone: Change) for backup data files, which allows local users to obtain sensitive information or modify the outcome of a restore via direct access to these files.
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Analysis
by VulDB Data Team • 05/21/2021
Symantec Backup Exec represents a critical enterprise-level data protection solution widely deployed across organizations for backup and recovery operations. The vulnerability identified in CVE-2013-4677 affects specific versions of this software, namely Backup Exec 2010 R3 before SP3 and Backup Exec 2012 before SP2, creating a significant security weakness that directly impacts the integrity and confidentiality of backup data. This issue manifests through improper file system permissions that grant excessive access rights to backup data files, fundamentally compromising the security posture of systems relying on this backup solution.
The technical flaw stems from the implementation of weak file permissions where backup data files are configured with "Everyone: Read" and "Everyone: Change" access rights. This configuration violates fundamental security principles by providing unrestricted access to backup data without proper authentication or authorization mechanisms. The vulnerability aligns with CWE-276, which addresses incorrect permissions for critical resources, and specifically represents a privilege escalation vector through improper access control. When backup data files are accessible to all users on the system, local attackers can directly access sensitive backup information, potentially obtaining confidential data that was supposed to be protected within the backup environment.
The operational impact of this vulnerability extends beyond simple information disclosure to encompass potential data integrity compromise. Local users with access to these backup files can modify backup data directly, which could result in corrupted backups or malicious alterations that would affect restore operations. This capability allows attackers to manipulate backup data to either hide malicious activities or create false recovery points that could be exploited during incident response or forensic investigations. The vulnerability creates a persistent threat vector that remains active as long as the affected software version is deployed, making it particularly dangerous for environments where backup data contains sensitive corporate or personal information.
From a threat modeling perspective, this vulnerability maps directly to ATT&CK technique T1070.004, which covers "File Deletion" and related data manipulation activities, and T1567.002, which addresses "Exfiltration Over Web Service" through local data access. The weak permissions create an environment where attackers can bypass traditional network-based security controls by leveraging local system access to directly manipulate backup files. Organizations using affected versions of Symantec Backup Exec face potential regulatory compliance violations, as backup data often contains personally identifiable information and other sensitive data requiring protection under various data protection regulations. The vulnerability demonstrates a critical failure in the principle of least privilege implementation, where backup data should be protected by robust access controls rather than open permissions that expose sensitive information to unauthorized local users. Organizations should immediately implement patches for SP3 for Backup Exec 2010 R3 and SP2 for Backup Exec 2012 to remediate this vulnerability and consider implementing additional monitoring for unauthorized access to backup files.