CVE-2018-0203

A vulnerability in the SMTP relay of Cisco Unity Connection could allow an unauthenticated, remote attacker to send unsolicited email messages, aka a Mail Relay Vulnerability. The vulnerability is due to improper handling of domain information in the affected software. An unauthenticated, remote attacker could exploit this vulnerability by sending crafted requests to the targeted application. A successful exploit could allow the attacker to send email messages to arbitrary addresses. Cisco Bug IDs: CSCvg62215.

Published: 2018-02-21 Last update: 2026-06-16 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2018-0203 is rated Moderate Risk (46.8/100): CVSS Medium severity, with medium exploitation likelihood (EPSS 1.62%). Review affected assets and schedule remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2018-0203

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-07-01 1.65% 1.62% -0.03%
2 2026-06-15 0.75% 1.65% +0.90%
3 2025-05-22 — 0.75% —

Full EPSS history (10 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2018-0203

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
5.3 3.0 MEDIUM
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:N)
Service keeps running; no real outage angle.
 3.9 1.4 [email protected]
5.0 2.0 MEDIUM
AV:N/AC:L/Au:N/C:N/I:P/A:N Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:N)
No confidentiality impact.
Integrity impact (I:P)
Partial integrity impact.
Availability impact (A:N)
No availability impact.
 10.0 2.9 [email protected]

Weakness enumeration for CVE-2018-0203

Affected software / configurations for CVE-2018-0203

Vendor Product Version Raw CPE
cisco unity_connection — cpe:2.3:a:cisco:unity_connection:-:*:*:*:*:*:*:*

References for CVE-2018-0203

cvelogic Threat Intelligence