Remote code execution via unchecked stack copy
Published Dec 1, 2021 · Updated Aug 3, 2024
Stack buffer overflow in D-Link DIR-809 firmware 1.12WWB03 and earlier allows remote attackers to execute code via a crafted POST request. The formVirtualApp handler uses get_var to read an attacker-controlled name_%d value, then strcpy copies it into the local_f8 stack buffer without checking its length. The attack requires network access to the router web interface; successful exploitation grants arbitrary code execution.
Summary
What happened
Stack buffer overflow in D-Link DIR-809 firmware 1.12WWB03 and earlier allows remote attackers to execute code via a crafted POST request. The formVirtualApp handler uses get_var to read an attacker-controlled name_%d value, then strcpy copies it into the local_f8 stack buffer without checking its length. The attack requires network access to the router web interface; successful exploitation grants arbitrary code execution.
The record
- CVE
- CVE-2021-33266
- Published
- Dec 1, 2021
- Updated
- Aug 3, 2024
- Vendor
- Unknown vendor
- Product
- Unknown product
- Classifications
- CWE-787, T1190
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Dec 1, 2021CVE publishedPublication date reported by the CVE source.
- Aug 3, 2024Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
What conditions does exploitation require?
What is affected?
Affected products and versions are unavailable in this record.
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.
Public exploit references
- D-Link DIR-809 formVirtualApp HTTP POST 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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