CVE-2021-27335 json
KollectApps before 4.8.16c is affected by insecure Java deserialization, leading to Remote Code Execution via a ysoserial.payloads.CommonsC…
published 2021-02-18 5 y ago modified 2026-06-17 4 mo ago also EUVD-2021-14095
- cvss
- 9.8
- version 3.1, NVD
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 3.0%
- EPSS 3.0% chance of exploitation in 30 days, percentile 87%
- public exploits
- 0
- none known
Summary
KollectApps before 4.8.16c is affected by insecure Java deserialization, leading to Remote Code Execution via a ysoserial.payloads.CommonsCollections parameter.
Patch / fix
- kollectapp kollect 4.8.16c
Exploit prediction
3.00% chance of exploitation in the next 30 days, higher than 87% of all scored CVEs (FIRST EPSS, 2026-11-08).
Exploits and checks
- hacked0x90.net https://hacked0x90.net/index.php/2021/02/15/kollectapp-insecure-java-deserialization/ referenced PoC, tagged "exploit" by a source, unverified
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| NVD | 3.1 | 9.8 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
| NVD | 2.0 | 7.5 | AV:N/AC:L/Au:N/C:P/I:P/A:P |
Classification
- Weakness
-
- CWE-502 Deserialization of Untrusted Data
References
-
hacked0x90.net
/index.php/2021/02/15/kollectapp-insecure-java-deserialization/
exploit, third-party-advisory
Sources
- CVE List CVE-2021-27335
- NVD CVE-2021-27335
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.