CVE Intelligence
CISA KEV High Access control exploit reference

CVE-2017-16651 — Roundcube Webmail File Disclosure Vulnerability

Roundcube Webmail before 1.1.10, 1.2.x before 1.2.7, and 1.3.x before 1.3.3 allows unauthorized access to arbitrary files on the host's filesystem, including configuration files, as exploited in the wild in November 2017. The attacker must be able to authenticate at the target system with a valid username/password as the attack requires an active session. The issue is related to file-based attachment plugins and _task=settings&_action=upload-display&_from=timezone requests.

Published Nov 9, 2017 · Updated Oct 13, 2026 · Sources: CISA Known Exploited Vulnerabilities, CVE Program (cve.org) e CISA ADP, NIST National Vulnerability Database, GitHub Security Advisories · CNA: mitre

Who exploits it and how urgent it is

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

CISA KEV · Nov 3, 2021 Metasploit modules · 1
How the score was calculated
  • Confirmed exploitation (CISA KEV)+35
  • Public exploit/PoC (metasploit)+12
  • EPSS 45.7% (30-day exploitation probability)+15
  • Technical severity (high)+6

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
Confirmed
CISA KEV, listed Nov 3, 2021
EPSS FIRST
45.74%
ahead of 99% of scored CVEs · Oct 14, 2026
Affects
Debian
Debian Linux and 1 more
CVSS base
7.8
High · 4 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
Active
none · proof-of-concept · active
Automatable
No
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.

  • Documented patch — github.com (NIST National Vulnerability Database)

CISA required action CISA

Apply updates per vendor instructions.

US federal deadline: May 3, 2022 — passed 1626 day(s) ago

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 (Debian Debian Linux, Roundcube Webmail).
  2. Treat as emergency remediation: the CVE is in CISA KEV (confirmed exploitation).
  3. Apply the fixed version or the patch documented under Remediation.
  4. EPSS ahead of 99% of scored CVEs: prioritize it in the patch queue.
  5. Search available logs for exploit probes matching the vulnerability class (access control), errors and authentication anomalies.

Affected scope

Vendor, product and versions as the sources word them.

VendorProductVersionsStatusSource
Debian Debian Linux version 7.0version 9.0 Vulnerable NIST National Vulnerability Database
Roundcube Webmail ≤ 1.1.9version 1.2.0version 1.2.1version 1.2.2version 1.2.3version 1.2.4version 1.2.5version 1.2.6
and 3 more version 1.3.0version 1.3.1version 1.3.2
Vulnerable NIST National Vulnerability Database

Attack characteristics

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

Attack vector
Local
Attack complexity
Low
Privileges required
Low
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

Every base score collected

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

ScoreVersionSeverityExpl.ImpactScored by
7.8 CVSS 3.1 High 1.8 5.9 nvd@nist.gov via NIST National Vulnerability Database
7.8 CVSS 3.1 High 1.8 5.9 134c704f-9b21-4f2e-91b3-4a467353bcc0 via NIST National Vulnerability Database
7.8 CVSS 3.1 High — — GitHub, Inc. via GitHub Security Advisories
7.8 CVSS 3.1 High — — CISA-ADP via CVE Program (cve.org) e CISA ADP
4.6 CVSS 2.0 Medium 3.9 6.4 nvd@nist.gov via NIST National Vulnerability Database
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H (score shown at the top: nvd@nist.gov)

Weakness MITRE

Weakness class according to MITRE’s CWE catalog.

CWE-552 · Files or Directories Accessible to External Parties

Other CVEs with this weakness →

CISA KEV details CISA

CISA lists a CVE once it has evidence of exploitation against real targets.

Listed
Nov 3, 2021
Federal deadline
May 3, 2022
passed 1626 day(s) ago
Ransomware use
Unknown

CISA records ransomware use only for campaigns it has confirmed, so “Unknown” means unrecorded, not ruled out. The deadline binds US federal agencies; for everyone else it is a reference date.

Public exploits, PoCs and detection templates

Public code that demonstrates or tests the flaw raises the odds of mass exploitation — and Nuclei templates help find vulnerable assets in your environment.

Metasploit modules

Warning: public PoCs are sometimes disguised malware. Use them only for authorized testing in an isolated environment. This portal does not host exploit code — it only points to the sources.

EPSS over time FIRST

Oct 13, 2026 → Oct 14, 2026 · 2 reading(s) · max 45.74%

Detection

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

  • Local/physical vector: focus on endpoint telemetry (EDR) from affected hosts.
  • Audit administrative actions and access to resources outside each user’s normal pattern.
  • Hunt retroactively in logs from before Nov 3, 2021 (KEV listing): exploitation may have started earlier.
endpoint telemetry (EDR)authentication logsapplication logs

Timeline

What happened to this CVE, newest first.

  • 2026
  • Fix documented
    Oct 13, 2026 · NIST National Vulnerability Database
  • Affected products added · roundcube/webmail, debian/debian linux
    Oct 13, 2026 · NIST National Vulnerability Database
  • Source status changed · Published → Analyzed
    Oct 13, 2026 · NIST National Vulnerability Database
  • Record published
    Oct 13, 2026
  • CVSS changed · 7.8
    Oct 13, 2026 · CVE Program (cve.org) e CISA ADP
  • Source status changed · → Published
    Oct 13, 2026 · CVE Program (cve.org) e CISA ADP
  • SSVC assessment updated
    Oct 13, 2026 · CVE Program (cve.org) e CISA ADP
  • Added to CISA KEV (detected)
    Oct 13, 2026 · CISA Known Exploited Vulnerabilities
  • Record created in this database
    Oct 13, 2026 · CISA Known Exploited Vulnerabilities
  • 2021
  • Added to CISA KEV catalog
    Nov 2, 2021 · CISA
  • 2017
  • CVE published
    Nov 9, 2017 · mitre

Source activity

Repeated readings are counted rather than listed.

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

References

12 on the record

Elsewhere on this site

Debian
every CVE for this vendor
2021-11
what else CISA listed that month
Access control
same class
CWE-552
other pages naming this weakness

Related CVEs (same products)

  • CVE-2026-12996 A use-after-free in OpenVPN 2.6.0 through 2.6.20 and 2.7_alpha1 through 2.7.4 allows remote... Jul 30, 2026
  • CVE-2026-14355 Heap-based Buffer Overflow in Php Jul 3, 2026
  • CVE-2026-56968 Use of Uninitialized Resource in Gnu Sasl Jun 23, 2026
  • CVE-2026-49975 Apache HTTP Server: mod_http2 denial of service Jun 8, 2026
  • CVE-2026-48848 Cross-site Scripting (XSS) in Roundcube Webmail May 25, 2026
  • CVE-2026-48849 Cross-site Scripting (XSS) in Roundcube Webmail May 25, 2026

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 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-2017-16651 is "Roundcube Webmail File Disclosure Vulnerability", rated High. It affects Debian Linux (Debian); versions are in the scope table. It is in CISA KEV: there is evidence of real-world exploitation. CVSS 7.8 describes technical severity. EPSS 45.74% 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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