This vulnerability (CVE-2025-71255) in Unisoc (Shanghai) Technologies modem chipsets SC7731E, SC9832E, SC9863A, and others affects the IMS subsystem due to improper input validation (CWE-20). The flaw allows an unauthenticated remote attacker to trigger a denial of service condition, impacting availability but not confidentiality or integrity. The affected products run Android versions 13 through 16. The CVSS 3.1 base score is 7.5, reflecting network attack vector, low attack complexity, no privileges required, no user interaction, and impact limited to availability. No patch or official remediation has been disclosed by Unisoc as of the publication date.

Successful exploitation results in remote denial of service against the modem IMS component, causing service disruption without requiring any privileges or user interaction. There is no impact on confidentiality or integrity. The affected devices running specified Android versions on Unisoc chipsets may experience modem service interruptions.

Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Since no official fix or temporary mitigation is currently available from Unisoc, affected users and organizations should monitor vendor communications for updates. No specific mitigations are documented at this time.