How severe is CVE-2018-0203?

CVE-2018-0203 has a CVSS 3.x base score of 5.3, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity low, and availability none.

Is CVE-2018-0203 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (73rd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2018-0203?

CVE-2018-0203 affects Cisco Unity Connection. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2018-0203?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2018-0203 published?

CVE-2018-0203 was published on 2018-02-22 and last updated on 2026-06-17.

CVE-2018-0203

CVE-2018-0203 is a medium-severity vulnerability in Cisco Unity Connection with a CVSS 3.x base score of 5.3. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-19.

Key facts

Severity: Medium (CVSS 3.x base score 5.3)
CVSS v2: 5.0
EPSS exploit prediction: 2% (73rd percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-19
Affected product: Cisco Unity Connection
Published: 2018-02-22
Last modified: 2026-06-17

Description

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.

Frequently asked questions

What is 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.
How severe is CVE-2018-0203?: CVE-2018-0203 has a CVSS 3.x base score of 5.3, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity low, and availability none.
Is CVE-2018-0203 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (73rd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2018-0203?: CVE-2018-0203 affects Cisco Unity Connection. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2018-0203?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2018-0203 published?: CVE-2018-0203 was published on 2018-02-22 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:cisco:unity_connection:-:*:*:*:*:*:*:*

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