CVE-2021-40524
HIGH NUCLEIPure-FTPd 1.0.23-1.0.49 - Unrestricted File Upload and Denial of Service via Incorrect Max Filesize Quota
Title source: llmExploitation Summary
CVE-2021-40524 has a Nuclei detection template available — see the Nuclei card below for the Shodan/FOFA recon queries.
Description
In Pure-FTPd before 1.0.50, an incorrect max_filesize quota mechanism in the server allows attackers to upload files of unbounded size, which may lead to denial of service or a server hang. This occurs because a certain greater-than-zero test does not anticipate an initial -1 value. (Versions 1.0.23 through 1.0.49 are affected.)
Nuclei Templates (1)
Pure-FTPd 1.0.23 < 1.0.50 - Arbitrary File Upload
HIGHVERIFIEDby pussycat0x
Shodan:
product:"pure-ftpd" version:"1.0.45" || cpe:"cpe:2.3:a:pureftpd:pure-ftpd"
References (4)
Core 4
Core References
Exploit, Third Party Advisory x_refsource_misc
https://github.com/jedisct1/pure-ftpd/pull/158
Patch, Third Party Advisory x_refsource_confirm
https://github.com/jedisct1/pure-ftpd/compare/1.0.49...1.0.50
Patch, Third Party Advisory x_refsource_confirm
https://github.com/jedisct1/pure-ftpd/commit/37ad222868e52271905b94afea4fc780d83294b4
Scores
CVSS v3
7.5
EPSS
0.0439
EPSS Percentile
90.0%
Attack Vector
NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Details
CWE
CWE-434
Status
published
Products (1)
pureftpd/pure-ftpd
1.0.23 - 1.0.50
Published
Sep 05, 2021
Tracked Since
Feb 18, 2026