Predictive Vulnerability Intelligence.

Product

  • Product
  • Pricing
  • Documentation

Company

  • About
  • Partnerships
  • Blog
  • Support

Legal

  • Terms
  • Privacy
  • Data Licensing

© 2026 FAUCET Technologies LLC. All rights reserved.

CVE-2021-40524

37
FAUCET Score

CVE-2021-40524 describes a denial-of-service vulnerability in Pure-FTPd versions 1.0.23 through 1.0.49, where an attacker can bypass the max_filesize quota to upload unbounded files, potentially crashing the server. This high-severity flaw (CVSS 7.5) is easily exploitable over the network without authentication, leading to high availability impact. While not currently listed on CISA's KEV catalog or showing active exploitation, a Nuclei template exists, indicating potential for exploit development, though there is minimal community discussion or media coverage.

Impacted Technologies

VendorProductVersion(s)CPE
>= 1.0.23, < 1.0.50CPE matchmatch criteria
cpe:2.3:a:pureftpd:pure-ftpd:*:*:*:*:*:*:*:*

CVSS Data

CVSS version used by this source: 3.1

7.5HIGH

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
NONE
Integrity Impact
NONE
Availability Impact
HIGH
Exploitability Score
3.9
Impact Score
3.6
CvssVersion
3.1

Exploit Intelligence

EPSS Score
4.29%
Probability of exploitation in next 30 days
EPSS Percentile
90.1%
Percentile rank of EPSS score among Peer Group
As of 2026-07-27
Model: v2026.06.15
Nuclei: CVE-2021-40524 · Oct 2, 2025
This CVE's current EPSS score of 0.0428 is in the 82nd percentile among its peer group of 51,506 CVEs.

Social Chatter

The average CVE in this peer group has 0.0 Twitter, 0.0 Reddit, 0.1 Bluesky, 0.1 Mastodon, and 0.4 GitHub mentions.

Media Mentions

No media coverage found for this CVE.

The average CVE in this peer group has 0.1 InfoSec Media, 0.0 Vendor Blog, and 0.0 Security Researcher mentions.

Remediation

Patch Available

Vendor Patches (1)

github_advisorypatch availablevia nvd_reference
View patch

References

lists.debian.org / debian-lts-announce/2025/11/msg00003.html
github.com / jedisct1/pure-ftpd/commit/37ad222868e52271905b94afea4fc780d83294b4
PatchThird Party Advisory
github.com / jedisct1/pure-ftpd/compare/1.0.49...1.0.50
PatchThird Party Advisory
github.com / jedisct1/pure-ftpd/pull/158
ExploitThird Party Advisory