HOMEVULNERABILITIESCVE-2019-5456
HIGH

CVE-2019-5456

CWE-300Published: July 30, 2019· Updated: Jun 17, 2026

8.1
CVSS v3.1

Official Description

SMTP MITM refers to a malicious actor setting up an SMTP proxy server between the UniFi Controller version <= 5.10.21 and their actual SMTP server to record their SMTP credentials for malicious use later.

NVD Source

Technical Analysis

CVE-2019-5456 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.

A successful exploit results in complete confidentiality breach (data exposure), full integrity compromise (data manipulation), availability disruption (denial of service), with a CVSS base score of 8.1.

CVSS v3.1 Vector Breakdown

Exploitability
Attack VectorNetwork
Attack ComplexityHigh
Privileges Req.None
User InteractionNone
ScopeUnchanged
Impact
ConfidentialityHigh
IntegrityHigh
AvailabilityHigh
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected Vendors & Products

ui1 product(s)
unifi controller
Source: NVD CPE · 1 total CPE entries

Exploit & PoC Resources

NO KNOWN EXPLOITNo public exploit confirmed at this time
Exploit-DB
Offensive Security exploit database
GitHub PoC Search
Community PoC repositories
Rapid7 / Metasploit
Metasploit module search
PacketStorm
Security advisories & exploits
NVD Detail
Official NIST entry
MITRE CVE
CVE Program entry
External links open in a new tab. Always verify in a controlled environment before use.

Official Patches & Advisories

ADVISORYhttps://community.ui.com/releases/862b962b-55f6-4324-96be-610f647d5c1c
ADVISORYhttps://community.ui.com/releases/9f698d0b-8279-40d3-9f1a-d36db4813124
ADVISORYhttps://community.ui.com/releases/Security-Advisory-Bulletin-003-003/982bbaa8-2a07-4f81-a5f6-0bb84753f391
ADVISORYhttps://community.ui.com/releases/862b962b-55f6-4324-96be-610f647d5c1c
ADVISORYhttps://community.ui.com/releases/9f698d0b-8279-40d3-9f1a-d36db4813124
ADVISORYhttps://community.ui.com/releases/Security-Advisory-Bulletin-003-003/982bbaa8-2a07-4f81-a5f6-0bb84753f391

All References (8)

→
https://community.ui.com/releases/862b962b-55f6-4324-96be-610f647d5c1cRelease Notes · Vendor Advisory
→
https://community.ui.com/releases/9f698d0b-8279-40d3-9f1a-d36db4813124Release Notes · Vendor Advisory
→
https://community.ui.com/releases/Security-Advisory-Bulletin-003-003/982bbaa8-2a07-4f81-a5f6-0bb84753f391Vendor Advisory
→
https://hackerone.com/reports/519582Permissions Required
→
https://community.ui.com/releases/862b962b-55f6-4324-96be-610f647d5c1cRelease Notes · Vendor Advisory
→
https://community.ui.com/releases/9f698d0b-8279-40d3-9f1a-d36db4813124Release Notes · Vendor Advisory
→
https://community.ui.com/releases/Security-Advisory-Bulletin-003-003/982bbaa8-2a07-4f81-a5f6-0bb84753f391Vendor Advisory
→
https://hackerone.com/reports/519582Permissions Required

Quick Facts

CVE IDCVE-2019-5456
CVSS Score8.1 / 10
SeverityHIGH
WeaknessCWE-300
CISA KEVNo
Affected1 vendor(s)
PublishedJul 30, 2019

Related CVEs (CWE-300)

CVE-2019-3793
9.8
CVE-2017-7480
9.8
CVE-2023-31004
9.0
CVE-2024-31206
8.2
CVE-2020-11024
8.2
CVE-2021-21953
8.1

Recommended Actions

  • →Apply vendor patches immediately
  • →Monitor CVE-2019-5456 in threat intel feeds
  • →Review IDS/IPS signatures for exploitation attempts
Data sourced from NVD (NIST), CISA KEV, and EPSS (FIRST). Analysis generated by CTIWATCH.COM. CVE data is provided under the NVD usage policy.
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