Remote code execution via unchecked nextitem pointer
Published Mar 6, 2020 · Updated Jan 21, 2026
Buffer overflow in netkit telnetd through 0.17 allows remote attackers to execute arbitrary code via crafted Telnet traffic. The nextitem function in utility.c reads beyond the netobuf or nbackp boundary and processes attacker-crafted escape bytes, enabling memory disclosure and code execution. A reachable, enabled telnetd service is required; exploitation can expose process memory before arbitrary code runs in the daemon's context.
Summary
What happened
Buffer overflow in netkit telnetd through 0.17 allows remote attackers to execute arbitrary code via crafted Telnet traffic. The nextitem function in utility.c reads beyond the netobuf or nbackp boundary and processes attacker-crafted escape bytes, enabling memory disclosure and code execution. A reachable, enabled telnetd service is required; exploitation can expose process memory before arbitrary code runs in the daemon's context.
The record
- CVE
- CVE-2020-10188
- Published
- Mar 6, 2020
- Updated
- Jan 21, 2026
- Vendor
- Unknown vendor
- Product
- Unknown product
- Classifications
- CWE-120, T1190
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Mar 6, 2020CVE publishedPublication date reported by the CVE source.
- Jan 21, 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?
What conditions does exploitation require?
What is affected?
Affected products and versions are unavailable in this record.
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
- Bravestarr telnetd proof-of-conceptproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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