Unauthenticated code execution via unchecked LLMNR name
Published Feb 4, 2022 · Updated Apr 15, 2025
Stack buffer overflow in the LLMNR service of Sealevel Systems SeaConnect 370W 1.3.34 allows remote attackers to execute code. The LLMNR query parser copies an attacker-supplied name into a 32-byte stack buffer without validating its one-byte length, permitting up to 255 controlled bytes to overwrite the stack. An unauthenticated attacker with network reachability to the LLMNR service can control the program counter and execute code on the appliance.
Summary
What happened
Stack buffer overflow in the LLMNR service of Sealevel Systems SeaConnect 370W 1.3.34 allows remote attackers to execute code. The LLMNR query parser copies an attacker-supplied name into a 32-byte stack buffer without validating its one-byte length, permitting up to 255 controlled bytes to overwrite the stack. An unauthenticated attacker with network reachability to the LLMNR service can control the program counter and execute code on the appliance.
The record
- CVE
- CVE-2021-21960
- Published
- Feb 4, 2022
- Updated
- Apr 15, 2025
- Vendor
- Sealevel Systems, Inc.
- Product
- SeaConnect 370W
- Classifications
- CWE-1284, CWE-121, T0866
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Feb 4, 2022CVE publishedPublication date reported by the CVE source.
- Apr 15, 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=Sealevel Systems, Inc. SeaConnect 370W v1.3.34
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
- Cisco Talos crafted LLMNR query demonstrationproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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