Dell AppSync 4.6.0 UNIX Symbolic Link Following Vulnerability (CVE-2026-22767)

Dell AppSync version 4.6.0 contains a UNIX Symbolic Link (Symlink) Following vulnerability, identified as CVE-2026-22767. This vulnerability enables a low-privileged attacker with local access to exploit the system and potentially tamper with sensitive information. The vulnerability was disclosed on April 1, 2026. Defenders should be aware of the potential for local privilege escalation and information tampering due to this vulnerability. Addressing this vulnerability is critical to maintaining the integrity and confidentiality of data managed by Dell AppSync.

Attack Chain

1. Attacker gains local access to the system running Dell AppSync 4.6.0.
2. Attacker identifies a directory writable by low-privileged users where AppSync improperly handles symlinks.
3. Attacker creates a malicious symbolic link pointing to a sensitive system file (e.g., /etc/shadow, configuration files).
4. AppSync, while performing its normal operations, follows the symbolic link created by the attacker.
5. AppSync attempts to access or modify the target file through the symlink.
6. Due to insufficient permission checks, AppSync inappropriately overwrites, reads, or modifies the sensitive file.
7. Attacker leverages the modified sensitive file to escalate privileges or gain unauthorized access.
8. Attacker achieves the objective of information tampering by modifying application data.

Impact

Successful exploitation of CVE-2026-22767 can lead to information tampering on systems running Dell AppSync 4.6.0. A low-privileged attacker with local access could potentially modify system or application configurations, leading to unauthorized access or disruption of services. The impact includes potential data corruption, privilege escalation, and a compromise of the overall system security posture.

Recommendation

• Apply the security update provided by Dell as detailed in DSA-2026-163 to remediate CVE-2026-22767 (https://www.dell.com/support/kbdoc/en-us/000446965/dsa-2026-163-security-update-for-dell-appsync-vulnerabilities).
• Implement the “Detect Suspicious Symlink Creation” Sigma rule to identify potentially malicious symlink activity on systems running Dell AppSync.
• Monitor file system events for unexpected modifications to sensitive files, particularly those targeted by symlinks, using the “Detect Sensitive File Tampering via Symlink” Sigma rule.