CVE Intelligence
Critical File handling exploit reference

CVE-2019-25714 — Seeyon OA A8 Unauthenticated Arbitrary File Write via htmlofficeservlet

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).

Published Apr 21, 2026 · Updated Oct 13, 2026 · Sources: NIST National Vulnerability Database, CVE Program (cve.org) e CISA ADP · CNA: VulnCheck

Who exploits it and how urgent it is

A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.

No exploitation signal in the sources consulted so far.
How the score was calculated
  • EPSS 0.7% (30-day exploitation probability)+8
  • Technical severity (critical)+10
  • CISA SSVC: exploitation "poc"+5
  • Automatable exploitation (SSVC)+3

The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).

Triage

Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.

Exploitation
Not confirmed
Not in CISA KEV — an absence of record, not proof it is unexploited.
EPSS FIRST
0.65%
ahead of 50% of scored CVEs · Oct 14, 2026
Affects
Seeyon Internet Software
A8-V5 Collaborative Management Software and 1 more
CVSS base
9.3
Critical · 2 source(s)

CISA SSVC assessment CISA

Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.

Exploitation
Proof of concept
none · proof-of-concept · active
Automatable
Yes
can an attacker script the kill-chain steps
Technical impact
Total
partial · total control of the vulnerable component

Remediation

Fixes and mitigations documented by the sources — linked to the original advisory.

No fix documented by the sources we poll. That does not mean none exists: check the vendor advisory.

First 24 hours

Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.

  1. Identify exposed assets running the affected vendor/product/version combinations (Seeyon Internet Software A8-V5 Collaborative Management Software, Seeyon Internet Software A8+ Collaborative Management Software).
  2. The attack is network-based and needs no privileges: restrict exposure (ACLs, VPN, WAF) until patched.
  3. No fix documented in the sources: reduce exposure and monitor the vendor advisory.
  4. Search available logs for exploit probes matching the vulnerability class (file handling), errors and authentication anomalies.

Affected scope

Vendor, product and versions as the sources word them.

VendorProductVersionsStatusSource
Seeyon Internet Software A8-V5 Collaborative Management Software version 6.1sp1 Vulnerable CVE Program (cve.org) e CISA ADP
Seeyon Internet Software A8+ Collaborative Management Software version 7.0version 7.0sp1version 7.0sp2version 7.0sp3version 7.1 Vulnerable CVE Program (cve.org) e CISA ADP

Attack characteristics

The CVSS vector, decoded. It describes the attack, not your exposure to it.

Attack vector
Network
Attack complexity
Low
Attack requirements
None
Privileges required
None
User interaction
None
Scope
X
Confidentiality (vulnerable system)
High
Integrity (vulnerable system)
High
Availability (vulnerable system)
High
Confidentiality (subsequent)
None
Integrity (subsequent)
None
Availability (subsequent)
None

Every base score collected

Sources score independently and may disagree; each row says who scored it and under which version.

ScoreVersionSeverityExpl.ImpactScored by
9.3 CVSS 4.0 Critical — — disclosure@vulncheck.com via NIST National Vulnerability Database
9.3 CVSS 4.0 Critical — — VulnCheck via CVE Program (cve.org) e CISA ADP
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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X (score shown at the top: disclosure@vulncheck.com)

Weakness MITRE

Weakness class according to MITRE’s CWE catalog.

CWE-434 · Unrestricted Upload of File with Dangerous Type

Other CVEs with this weakness →

EPSS over time FIRST

Oct 13, 2026 → Oct 14, 2026 · 2 reading(s) · max 0.65%

Detection

Read off the CVSS vector and the weakness class. Starting points, not tested rules.

  • Prioritize edge telemetry for the network-reachable component (proxy, WAF, IDS/IPS).
  • Monitor file creation in web directories and paths with traversal sequences (../).
web/proxy/WAF logsnetwork IDS/IPSfile integrity (FIM)endpoint telemetry (EDR)

Analysis and videos

CVE-2019-25714: Seeyon OA A8 Unauthenticated Arbitrary File Write via htmlofficeservlet
CVE-2019-25714 affects Seeyon OA A8 and, as described in the record, lets an unauthenticated remote attacker write arbitrary files into the web application root through the /seeyon/htmlofficeservlet endpoint. The record classifies the flaw as CWE-434 and cites a CVSS 4.0 base score of 9.3 from VulnCheck, and notes that Shadowserver first observed exploitation evidence on 2021-03-26 (UTC). The record contains no affected version list, no fix information and no CISA KEV listing.

Timeline

What happened to this CVE, newest first.

  • 2026
  • Affected products added · seeyon internet software/a8-v5 collaborative management software, seeyon internet software/a8+ collaborative management
    Oct 13, 2026 · CVE Program (cve.org) e CISA ADP
  • SSVC assessment updated
    Oct 13, 2026 · CVE Program (cve.org) e CISA ADP
  • Record published
    Oct 13, 2026
  • CVSS changed · 9.3
    Oct 13, 2026 · NIST National Vulnerability Database
  • Source status changed · → Deferred
    Oct 13, 2026 · NIST National Vulnerability Database
  • Record created in this database
    Oct 13, 2026 · NIST National Vulnerability Database
  • CVE published
    Apr 21, 2026 · VulnCheck

Source activity

Repeated readings are counted rather than listed.

  • 1× Official description updated · Oct 13, 2026 – Oct 13, 2026

References

7 on the record

Elsewhere on this site

Seeyon Internet Software
every CVE for this vendor
File handling
same class
CWE-434
other pages naming this weakness

Not in any source we poll

Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.

  • No fixed version, patch or mitigation documented.
  • No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
  • No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
  • No exploit packet captures, log samples, or incident case IDs supplied.

Answered from this record

Text assembled only from the fields above — no additional claims.

What should defenders know first?

CVE-2019-25714 is "Seeyon OA A8 Unauthenticated Arbitrary File Write via htmlofficeservlet", rated Critical. It affects A8-V5 Collaborative Management Software (Seeyon Internet Software); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 9.3 describes technical severity. EPSS 0.65% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.

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