CVE-2025-66738
CVE-2025-66738 is a high-severity vulnerability in Yealink Sip-t21(p)e2 Firmware with a CVSS 3.x base score of 8.8. 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-77.
Key facts
- Severity: High (CVSS 3.x base score 8.8)
- EPSS exploit prediction: 1% (49th percentile)
- Actively exploited: Not listed in CISA KEV
- EU (EUVD) id: EUVD-2025-205450
- Weakness: CWE-77
- Affected product: Yealink Sip-t21(p)e2 Firmware
- Published:
- Last modified:
Description
An issue in Yealink T21P_E2 Phone 52.84.0.15 allows a remote normal privileged attacker to execute arbitrary code via a crafted request the ping function of the diagnostic component.
Frequently asked questions
- What is CVE-2025-66738?
- An issue in Yealink T21P_E2 Phone 52.84.0.15 allows a remote normal privileged attacker to execute arbitrary code via a crafted request the ping function of the diagnostic component.
- How severe is CVE-2025-66738?
- CVE-2025-66738 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
- Is CVE-2025-66738 being actively exploited?
- It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (49th percentile), an estimate of the probability of exploitation in the next 30 days.
- What products are affected by CVE-2025-66738?
- CVE-2025-66738 affects Yealink Sip-t21(p)e2 Firmware. See the affected-products list for the exact vulnerable versions.
- How do I fix CVE-2025-66738?
- 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.
- Does CVE-2025-66738 have an EU (EUVD) identifier?
- Yes. CVE-2025-66738 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-205450.
- When was CVE-2025-66738 published?
- CVE-2025-66738 was published on 2025-12-26 and last updated on 2026-10-07.
References
EU advisories (EUVD)
Affected products (1)
- cpe:2.3:o:yealink:sip-t21\(p\)e2_firmware:52.84.0.15:*:*:*:*:*:*:*
More vulnerabilities in Yealink Sip-t21(p)e2 Firmware
- CVE-2025-66737 — Medium (CVSS 4.3): Yealink T21P_E2 Phone 52.84.0.15 is vulnerable to Directory Traversal. A remote normal privileged attacker can read…
All CVEs affecting Yealink Sip-t21(p)e2 Firmware →
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