Seeyon OA A8 contains an unauthenticated arbitrary file write vulnerability in the /seeyon/htmlofficeservlet endpoint that allows remote attackers to write arbitrary files to the web application root by sending specially crafted POST requests with custom base64-encoded payloads. Attackers can write JSP webshells to the web root and execute them through the web server to achieve arbitrary OS command execution with web server privileges. Exploitation evidence was first observed by the Shadowserver Foundation on 2021-03-26 (UTC).
History

Wed, 22 Apr 2026 12:15:00 +0000

Type Values Removed Values Added
First Time appeared Seeyon Internet Software
Seeyon Internet Software a8+ Collaborative Management Software
Seeyon Internet Software a8-v5 Collaborative Management Software
Vendors & Products Seeyon Internet Software
Seeyon Internet Software a8+ Collaborative Management Software
Seeyon Internet Software a8-v5 Collaborative Management Software

Wed, 22 Apr 2026 00:00:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'poc', 'Technical Impact': 'total'}, 'version': '2.0.3'}


Tue, 21 Apr 2026 16:30:00 +0000

Type Values Removed Values Added
Description Seeyon OA A8 contains an unauthenticated arbitrary file write vulnerability in the /seeyon/htmlofficeservlet endpoint that allows remote attackers to write arbitrary files to the web application root by sending specially crafted POST requests with custom base64-encoded payloads. Attackers can write JSP webshells to the web root and execute them through the web server to achieve arbitrary OS command execution with web server privileges. Exploitation evidence was first observed by the Shadowserver Foundation on 2021-03-26 (UTC).
Title Seeyon Office Anywhere (OA) A8 Unauthenticated Arbitrary File Write via htmlofficeservlet
Weaknesses CWE-434
References
Metrics cvssV4_0

{'score': 9.3, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N'}


cve-icon MITRE

Status: PUBLISHED

Assigner: VulnCheck

Published: 2026-04-21T16:11:54.961Z

Updated: 2026-04-21T20:37:38.941Z

Reserved: 2026-04-21T15:54:59.039Z

Link: CVE-2019-25714

cve-icon Vulnrichment

Updated: 2026-04-21T20:32:00.261Z

cve-icon NVD

Status : Deferred

Published: 2026-04-21T17:16:20.777

Modified: 2026-04-22T21:20:25.267

Link: CVE-2019-25714

cve-icon Redhat

No data.