In Cloudron 6.2, the returnTo parameter on the login page is vulnerable to Reflected XSS.

published 2021-09-21 5 y ago modified 2026-06-17 4 mo ago also EUVD-2021-28023

cvss: 6.1; version 3.1, NVD
cisa kev: Not listed; not in CISA's catalog
epss: 9.1%; EPSS 9.1% chance of exploitation in 30 days, percentile 95%
public exploits: 1; Exploit-DB, plus a Nuclei check

Timeline

2021-09-21 Published
2021-09-22 First public exploit (EDB-50317)

Exploit prediction

9.07% chance of exploitation in the next 30 days, higher than 95% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

EDB-50317 Cloudron 6.2 - 'returnTo ' Cross Site Scripting (Reflected) webapps, 2021-09-22
Nuclei template Cloudron 6.2 Cross-Site Scripting nuclei detection template
packetstormsecurity.com https://packetstormsecurity.com/files/164183/Cloudron-6.2-Cross-Site-Scripting.html referenced PoC, tagged "exploit" by a source, unverified
packetstormsecurity.com http://packetstormsecurity.com/files/164255/Cloudron-6.2-Cross-Site-Scripting.html referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by	version	score	vector
NVD	3.1	6.1	CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
NVD	2.0	4.3	AV:N/AC:M/Au:N/C:N/I:P/A:N

Classification

Weakness

CWE-79 Improper Neutralization of Input During Web Page Generation

References

packetstormsecurity.com /files/164183/Cloudron-6.2-Cross-Site-Scripting.html
exploit, third-party-advisory, vdb-entry
packetstormsecurity.com /files/164255/Cloudron-6.2-Cross-Site-Scripting.html
exploit, third-party-advisory
cloudron.io /
product

Sources

CVE List CVE-2021-40868
NVD CVE-2021-40868

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary