CVE-2025-21250:
A remote code execution vulnerability in Windows Telephony Service (TapiSrv) that can be exploited over the network to execute arbitrary code, rated HIGH (CVSS v3.1 base score 8.8). The exploit requires user interaction and does not require prior privileges, affecting a wide range of Windows client and server versions.
Score
A numerical rating that indicates how dangerous this vulnerability is.
8.8High- Published Date:Jan 14, 2025
- CISA KEV Date:*No Data*
- Industries Affected:20
Threat Predictions
- EPSS Score:0.9
- EPSS Percentile:76%
Exploitability
- Score:2.8
- Attack Vector:NETWORK
- Attack Complexity:LOW
- Privileges Required:NONE
- User Interaction:REQUIRED
- Scope:UNCHANGED
Impact
- Score:5.9
- Confidentiality Impact:HIGH
- Integrity Impact:HIGH
- Availability Impact:HIGH
Description Preview
A remote code execution vulnerability in Windows Telephony Service (TapiSrv) that can be exploited over the network to execute arbitrary code, rated HIGH (CVSS v3.1 base score 8.8). The exploit requires user interaction and does not require prior privileges, affecting a wide range of Windows client and server versions.
Overview
The Windows Telephony Service Remote Code Execution Vulnerability (CVE-2025-21250) is a heap-based buffer overflow in the Windows Telephony Service that can be exploited remotely over the network to achieve code execution on a vulnerable system. It carries a high severity rating with CVSS v3.1 base score of 8.8 and requires user interaction to trigger, though it does not require attacker privileges. The vulnerability affects a broad set of Windows client and server versions, spanning legacy to recent releases, as detailed in the security advisory. The impact is potentially severe, enabling attacker-controlled code execution with significant access depending on the target environment. Microsoft has released patches; immediate remediation is advised for affected systems.
Remediation
- Apply the latest Microsoft security updates for all affected Windows client and server versions as soon as they are available.
- Verify patch status on all systems listed in the advisory and ensure cumulative/security updates are installed and rebooted where required.
- If patches are temporarily unavailable, apply mitigations:
- Disable the Windows Telephony Service (TapiSrv) if it is not required in your environment.
- Restrict inbound network access to the Telephony service and related ports using firewalls; segment or isolate hosts running Telephony services where feasible.
- Ensure robust network security controls, including intrusion prevention and up-to-date endpoint protection.
- Validate patch deployment in a test environment before broad rollout.
- Monitor vendor advisories for any additional guidance or revised mitigations; perform a follow-up scan to confirm remediation.
- After patching, perform a post-implementation test and monitor for any unusual activity.
References
Industries Affected
Below is a list of industries most commonly impacted or potentially at risk based on intelligence.
