How severe is CVE-2018-16221?

CVE-2018-16221 has a CVSS 3.x base score of 8.0, rated high severity. It is exploitable over an adjacent network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2018-16221 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (71st percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2018-16221?

CVE-2018-16221 affects Yealink Ultra-elegant Ip Phone Sip-t41p Firmware. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2018-16221?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2018-16221 published?

CVE-2018-16221 was published on 2019-05-29 and last updated on 2026-06-17.

CVE-2018-16221

CVE-2018-16221 is a high-severity vulnerability in Yealink Ultra-elegant Ip Phone Sip-t41p Firmware with a CVSS 3.x base score of 8.0. 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-22.

Key facts

Severity: High (CVSS 3.x base score 8.0)
CVSS v2: 7.7
EPSS exploit prediction: 1% (71st percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-22
Affected product: Yealink Ultra-elegant Ip Phone Sip-t41p Firmware
Published: 2019-05-29
Last modified: 2026-06-17

Description

The diagnostics web interface in the Yeahlink Ultra-elegant IP Phone SIP-T41P (firmware 66.83.0.35) does not validate (escape) the path information (path traversal), which allows an authenticated remote attacker to get access to privileged information (e.g., /etc/passwd) via path traversal (relative path information in the file parameter of the corresponding POST request).

Frequently asked questions

What is CVE-2018-16221?: The diagnostics web interface in the Yeahlink Ultra-elegant IP Phone SIP-T41P (firmware 66.83.0.35) does not validate (escape) the path information (path traversal), which allows an authenticated remote attacker to get access to privileged information (e.g., /etc/passwd) via path traversal (relative path information in the file parameter of the corresponding POST request).
How severe is CVE-2018-16221?: CVE-2018-16221 has a CVSS 3.x base score of 8.0, rated high severity. It is exploitable over an adjacent network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2018-16221 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (71st percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2018-16221?: CVE-2018-16221 affects Yealink Ultra-elegant Ip Phone Sip-t41p Firmware. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2018-16221?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2018-16221 published?: CVE-2018-16221 was published on 2019-05-29 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:o:yealink:ultra-elegant_ip_phone_sip-t41p_firmware:66.83.0.35:*:*:*:*:*:*:*

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