CVE-2021-20787 json
Cross-site scripting vulnerability in GroupSession (GroupSession Free edition from ver2.2.0 to the version prior to ver5.1.0, GroupSession…
published 2021-07-28 5 y ago modified 2026-06-17 4 mo ago also EUVD-2021-8199
- cvss
- 4.8
- version 3.1, NVD
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.6%
- EPSS 0.6% chance of exploitation in 30 days, percentile 50%
- public exploits
- 0
- none known
Summary
Cross-site scripting vulnerability in GroupSession (GroupSession Free edition from ver2.2.0 to the version prior to ver5.1.0, GroupSession byCloud from ver3.0.3 to the version prior to ver5.1.0, and GroupSession ZION from ver3.0.3 to the version prior to ver5.1.0) allows a remote attacker to inject an arbitrary script by sending a specially crafted request to a specific URL.
Patch / fix
- groupsession groupsession 5.1.0
- groupsession groupsession_bycloud 5.1.0
- groupsession groupsession_zion 5.1.0
Exploit prediction
0.64% chance of exploitation in the next 30 days, higher than 50% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| NVD | 3.1 | 4.8 | CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:N |
| NVD | 2.0 | 3.5 | AV:N/AC:M/Au:S/C:N/I:P/A:N |
Affected products
- Japan Total System Co.,Ltd. GroupSession
Classification
- Weakness
-
- CWE-79 Improper Neutralization of Input During Web Page Generation
References
-
groupsession.jp
/info/info-news/security202107
vendor-advisory
-
jvn.jp
/en/jp/JVN86026700/index.html
third-party-advisory
Sources
- CVE List CVE-2021-20787
- NVD CVE-2021-20787
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