FTP service interruption via connection exhaustion
Published Aug 22, 2023 · Updated Oct 3, 2024
Resource exhaustion in vsftpd 3.0.3 allows remote attackers to interrupt FTP service by opening many concurrent connections. The connection handler accepts repeated unauthenticated sessions until the configured client limit is exhausted, after which legitimate users cannot connect. An exposed FTP listener is required, and the published exploit sustains the outage by continuously creating new connections, without reported data access or modification.
Summary
What happened
Resource exhaustion in vsftpd 3.0.3 allows remote attackers to interrupt FTP service by opening many concurrent connections. The connection handler accepts repeated unauthenticated sessions until the configured client limit is exhausted, after which legitimate users cannot connect. An exposed FTP listener is required, and the published exploit sustains the outage by continuously creating new connections, without reported data access or modification.
The record
- CVE
- CVE-2021-30047
- Published
- Aug 22, 2023
- Updated
- Oct 3, 2024
- Vendor
- Unknown vendor
- Product
- Unknown product
- Classifications
- T1498.001
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Aug 22, 2023CVE publishedPublication date reported by the CVE source.
- Oct 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.
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
- vsftpd 3.0.3 Remote Denial of Serviceproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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