How severe is CVE-2021-31645?

CVE-2021-31645 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2021-31645 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (76th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-31645?

CVE-2021-31645 affects Glftpd. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-31645?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2021-31645 published?

CVE-2021-31645 was published on 2022-07-07 and last updated on 2026-06-17.

CVE-2021-31645

CVE-2021-31645 is a high-severity vulnerability in Glftpd with a CVSS 3.x base score of 7.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-770.

Key facts

Severity: High (CVSS 3.x base score 7.5)
CVSS v2: 5.0
EPSS exploit prediction: 2% (76th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-770
Affected product: Glftpd
Published: 2022-07-07
Last modified: 2026-06-17

Description

An issue was discovered in glFTPd 2.11a that allows remote attackers to cause a denial of service via exceeding the connection limit.

Frequently asked questions

What is CVE-2021-31645?: An issue was discovered in glFTPd 2.11a that allows remote attackers to cause a denial of service via exceeding the connection limit.
How severe is CVE-2021-31645?: CVE-2021-31645 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2021-31645 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (76th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-31645?: CVE-2021-31645 affects Glftpd. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-31645?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2021-31645 published?: CVE-2021-31645 was published on 2022-07-07 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:glftpd:glftpd:2.11a:*:*:*:*:*:*:*

More vulnerabilities in Glftpd

CVE-2000-0587 — Critical (CVSS 10.0): The privpath directive in glftpd 1.18 allows remote attackers to bypass access restrictions for directories by using…
CVE-2000-0040 — Critical (CVSS 10.0): glFtpD allows local users to gain privileges via metacharacters in the SITE ZIPCHK command.
CVE-2006-1253 — High (CVSS 7.5): Unspecified vulnerability in glFTPd before 2.01 RC5 allows remote attackers to bypass IP checks via a crafted DNS…
CVE-2000-0038 — High (CVSS 7.5): glFtpD includes a default glftpd user account with a default password and a UID of 0.
CVE-2005-0483 — Medium (CVSS 5.0): Multiple directory traversal vulnerabilities in sitenfo.sh, sitezipchk.sh, and siteziplist.sh in Glftpd 1.26 to 2.00…
CVE-2001-0965 — Medium (CVSS 5.0): glFTPD 1.23 allows remote attackers to cause a denial of service (CPU consumption) via a LIST command with an argument…

All CVEs affecting Glftpd →

Other CWE-770 (Allocation of Resources Without Limits or Throttling) vulnerabilities

CVE-2026-31283 — Critical (CVSS 9.8): In Totara LMS v19.1.5 and before, the forgot password API does not implement rate limiting for the target email…
CVE-2020-37067 — Critical (CVSS 9.8): Filetto 1.0 FTP server contains a denial of service vulnerability in the FEAT command processing that allows attackers…
CVE-2021-47875 — Critical (CVSS 9.8): GeoGebra CAS Calculator 6.0.631.0 contains a denial of service vulnerability that allows attackers to crash the…
CVE-2025-11832 — Critical (CVSS 9.8): Allocation of Resources Without Limits or Throttling vulnerability in Azure Access Technology BLU-IC2, Azure Access…
CVE-2024-44241 — Critical (CVSS 9.8): The issue was addressed with improved bounds checks. This issue is fixed in iOS 18.1 and iPadOS 18.1, macOS Sequoia…
CVE-2022-3439 — Critical (CVSS 9.8): Allocation of Resources Without Limits or Throttling in GitHub repository ikus060/rdiffweb prior to 2.5.0.

Browse all CWE-770 (Allocation of Resources Without Limits or Throttling) vulnerabilities →