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Threats / Roundcube / CVE-2017-16651
CVE-2017-16651 · EUVD no mirror located · GCVE no mirror located Verified 2026-06-22

Roundcube Webmail vulnerability

Roundcube Webmail contains a file disclosure vulnerability due to insufficient input validation in file-based attachment plugins, allowing unauthorized access to files.

Verdict

Today item — known-exploited.

An unauthenticated or authenticated attacker can exploit insufficient input validation in Roundcube's attachment handling to disclose arbitrary files from the server, potentially exposing sensitive configuration data, credentials, or user information.

CISA KEV Yes · 2021-11-033EPSS 0.42831 (verify live)4Exploit Public PoC5
01

Is it exploitable?

— the evidence, ranked above the score
Exploit available
Public proof-of-concept exploit code is cataloged for this vulnerability.We link the existence of the exploit; we do not host or redistribute payloads.
Reported exploitation
3 independent public reports of in-the-wild exploitation are cataloged.Distinct reporting sources (vendor, incident response, government); open them for the underlying claims.
Exploited in the wild
Listed in the CISA Known Exploited Vulnerabilities catalog (added 2021-11-03).
CISA KEV ↗Confirmed
Probability (EPSS)
EPSS 0.42831 — modeled likelihood of exploitation activity.EPSS is a daily-changing model output — open the source for today's value.
Severity / affected
Affected: Roundcube, Roundcube Webmail. Confirm exact fixed builds in the vendor advisory.
NVD ↗Reported
Weakness (CWE)
Mapped to CWE-552 Files Accessible to External Parties — weakness family: Path traversal / file.CWE assignment from the public NVD record; the weakness class drives how the flaw is exploited.
NVD ↗Reported
02

Who’s exploiting it?

— attribution turns risk into urgency
Attribution not established

No confirmed (advisory-backed) threat-actor attribution is established for this record. Absence of a named actor is not absence of compromise — see Coverage & confidence.

03

Why it matters

— the attack path, told twice: adversary, then board
1

Front door — unauthenticated access narrative 1

Attacker
I craft a malicious request targeting the attachment plugin with path traversal sequences to bypass file access restrictions.
Business
Sensitive files including database credentials, configuration secrets, and user data become accessible to the attacker without authorization.
2

Keys to the kingdom — privilege/identity takeover narrative 2

Attacker
I retrieve exposed configuration files or private keys to escalate my access or pivot to other systems.
Business
Compromised credentials and system architecture details enable further intrusions, expanding the attack surface and increasing breach scope.
04

What to do

— defensible action
  • Remediate per the vendor advisory — confirm the fixed build for your version and verify exposure.1
Say it to the boardA vulnerability with this evidence profile is a defensible budget line, not a backlog ticket — fund the change against the proof above.
05

Coverage & confidence

— what we know, and what we don’t

Established (cited)

  • KEV listing (CISA)
  • EPSS probability (FIRST)
  • Public PoC available (VulnCheck)
  • 3 reported-exploitation source(s)
  • CWE weakness mapping (NVD)
  • Public exploit availability
  • Catalogued by mitre (CNA)
  • Coverage gaps — stated, not hidden

  • No EUVD / GCVE mirror in feed — single-authority dependency for the identifier.
  • EPSS & exposure are time-varying; verify live at the source.
  • Threat-actor attribution not established from feed data — absence of a name is not absence of compromise.
  • No finder/reporter credit recorded in the public CVE entry — the work behind this find is unattributed.
  • Disclosure & credit2
    Catalogued by mitreCNA
    Credited with finding itNo finder named in the public CVE record — the work behind this find is unattributed.