Security readout for executives and security teams
Plain-English summary
CVE-2021-31645 is a denial-of-service issue in glFTPd 2.11a. A remote attacker can disrupt availability by exceeding the service connection limit. The sources do not provide CVSS scoring, a vendor fix, or evidence of active exploitation.
Executive priority
Treat as a service-availability risk. Prioritize internet-facing or business-critical FTP services first, because the public record does not establish active exploitation or severity scoring.
Technical view
The CVE record describes glFTPd 2.11a as vulnerable to remote denial of service when the connection limit is exceeded. Public references include the glFTPd website and an Exploit-DB entry, but the supplied data does not identify affected CPEs, CWE, patch level, or detailed vendor remediation.
Likely exposure
Exposure is likely limited to systems running glFTPd 2.11a, especially if the FTP service is reachable from the internet or other untrusted networks.
Exploitation context
KEV is false, so the bundle does not support active exploitation claims. The Exploit-DB reference indicates public exploit-related information exists, but this analysis avoids operational details.
Researcher notes
The source bundle is sparse: no CVSS, CWE, CPE, patch, or detailed advisory data is provided. Avoid expanding scope beyond glFTPd 2.11a without vendor confirmation.
Mitigation direction
- Inventory systems for glFTPd 2.11a installations.
- Check glFTPd vendor guidance for fixed versions or configuration advice.
- Restrict FTP access to trusted networks where business allows.
- Monitor connection spikes and service restarts on exposed hosts.
- Place exposed services behind defensive rate limiting where available.
Validation and detection
- Confirm whether any asset runs glFTPd 2.11a.
- Verify whether glFTPd is reachable from the internet.
- Review logs for abnormal connection-limit exhaustion events.
- Check vendor and change-management records for upgrade status.
- Document compensating controls for any remaining exposed instance.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CVE-2021-31645 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- Unknown
- CVSS
- Not scored
- Known Exploited
- No
- Published
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS and timeline data
No CVSS vectors or timeline events were available in the normalized CVE source material.
Source materials
- CVE List V5 sourceCVE List V5
- https://glftpd.io/CVE reference · x_refsource_MISC
- https://www.exploit-db.com/exploits/49773CVE reference · x_refsource_MISC
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.