Authenticated code execution via unchecked f_idx copy
Published Mar 16, 2026 · Updated Mar 16, 2026
Stack-based overflow in D-Link storage appliances version 20260205 allows remote authenticated users to execute code or crash services. Local_Backup_Info in /cgi-bin/local_backup_mgr.cgi copies the attacker-controlled f_idx value into a stack variable without checking its length, overwriting the function return address. Reaching the CGI requires an authenticated web session; the published request uses an administrator cookie, and the demonstrated outcome is a persistent service crash.
Summary
What happened
Stack-based overflow in D-Link storage appliances version 20260205 allows remote authenticated users to execute code or crash services. Local_Backup_Info in /cgi-bin/local_backup_mgr.cgi copies the attacker-controlled f_idx value into a stack variable without checking its length, overwriting the function return address. Reaching the CGI requires an authenticated web session; the published request uses an administrator cookie, and the demonstrated outcome is a persistent service crash.
The record
- CVE
- CVE-2026-4211
- Published
- Mar 16, 2026
- Updated
- Mar 16, 2026
- Vendor
- D-Link
- Product
- DNR-322L
- Classifications
- CWE-787, CWE-119, CWE-121, T1499.004, T1190
- Attack vector
- network
- Privileges
- admin
Timeline
How it unfolded
- Mar 16, 2026CVE publishedPublication date reported by the CVE source.
- Mar 16, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
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- Affected versionversion=20260205
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- D-Link local_backup_mgr.cgi f_idx crash proof of conceptfunctional · demonstrated
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Technologies
Your stack
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Your stack
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