Authenticated data modification via unbounded sprintf
Published Nov 15, 2025 · Updated Nov 17, 2025
Stack overflow in D-Link DIR-816L 2_06_b09_beta allows remote authenticated users to alter router data or interrupt service via UNSUBSCRIBE. The sub_4134E0 path reached by genacgi_main concatenates attacker-controlled SERVER_ID and HTTP_SID values with sprintf into a fixed-size stack buffer. Low-privileged management access is required; published assessments also cover data disclosure, not only a crash.
Summary
What happened
Stack overflow in D-Link DIR-816L 2_06_b09_beta allows remote authenticated users to alter router data or interrupt service via UNSUBSCRIBE. The sub_4134E0 path reached by genacgi_main concatenates attacker-controlled SERVER_ID and HTTP_SID values with sprintf into a fixed-size stack buffer. Low-privileged management access is required; published assessments also cover data disclosure, not only a crash.
The record
- CVE
- CVE-2025-13189
- Published
- Nov 15, 2025
- Updated
- Nov 17, 2025
- Vendor
- D-Link
- Product
- DIR-816L
- Classifications
- CWE-121, CWE-119, T1190
- Attack vector
- network
- Privileges
- authenticated
Timeline
How it unfolded
- Nov 15, 2025CVE publishedPublication date reported by the CVE source.
- Nov 17, 2025Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=2_06_b09_beta
What conditions does exploitation require?
What is affected?
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
- DIR-816L gena.cgi stack-overflow proof of conceptproof of concept · demonstrated
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
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Your stack
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