ProFTPD 1.3.7a - Remote Denial of Service
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Attack requirements
- None
- Impact type
- Denial of service
- Confidentiality · integrity · availability
- None · None · High
- Fix status
- No fix listed
Attack profile from CVSS 4.0 · CNA. Fix status from CNA. Impact type from CWE-770.
Summary
ProFTPD 1.3.7a contains a denial of service vulnerability that allows attackers to overwhelm the server by creating multiple simultaneous FTP connections. Attackers can repeatedly establish connections using threading to exhaust server connection limits and block legitimate user access.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- Poc
- Automatable
- Yes
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
Remediation
No fixed version listed by the sources yet.
Vendor assessments
Timeline
- 2026-10-02 Threatist record created from CVE-2021-47865
- 2026-10-03 Alias added: GHSA-mf77-27mv-mhm4
References
Exploit 1
More ProFTPD vulnerabilities
- TI-2015-02923 Access control flaw in ProFTPD mod_copy allows arbitrary file access KEVCVSS 3.1CRITICAL 10.0
- TI-2010-03974 Multiple stack-based buffer overflows in the pr_netio_telnet_gets function in netio.c in… CVSS 2.0HIGH 10.0
- TI-2010-05061 ProFTPD 1.3.3c Backdoor Command Execution CVSS 4.0CRITICAL 9.3
- TI-2019-09597 An arbitrary file copy vulnerability in mod_copy in ProFTPD up to 1.3.5b allows for… CVSS 3.1CRITICAL 9.8
- TI-2026-30493 SQL injection in ProFTPD CVSS 3.1HIGH 8.1
- TI-2023-26623 The SSH transport protocol with certain OpenSSH extensions, found in OpenSSH before 9.6… CVSS 3.1MEDIUM 5.9
Sources
- CVE-2021-47865 · CVE Program
- CVE-2021-47865 · NVD
- FIRST EPSS
- GHSA-mf77-27mv-mhm4 · GitHub Advisory Database · CC BY 4.0
- CVE-2021-47865 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences