Is CVE-2021-27562 actively exploited?

Yes. CVE-2021-27562 is listed in the CISA Known Exploited Vulnerabilities (KEV) catalog, which means exploitation in the wild has been confirmed.

Can CVE-2021-27562 be exploited remotely?

The attack vector of CVE-2021-27562 has not been classified yet.

What is the CVSS score of CVE-2021-27562?

CVE-2021-27562 has not received a CVSS score yet.

HOME VULNERABILITIESCVE-2021-27562

HIGHCISA KEVIN THE WILD

CVE-2021-27562

Published: November 3, 2021

EPSS:54.16%probability of exploitation in 30 daysPercentile:98.0th

Official Description

Arm Trusted Firmware contains an out-of-bounds write vulnerability allowing the non-secure (NS) world to trigger a system halt, overwrite secure data, or print out secure data when calling secure functions under the non-secure processing environment (NSPE) handler mode. This vulnerability affects Yealink Device Management servers.

NVD Source

CISA KEV Advisory

Arm Trusted Firmware Out-of-Bounds Write Vulnerability

Added to KEV: 2021-11-03Federal patch deadline: 2021-11-17

Required Action (CISA)

Apply updates per vendor instructions.

Risk Analysis

An out-of-bounds write vulnerability in Arm Trusted Firmware can allow a non-secure environment to disrupt system operations, overwrite sensitive data, or leak secure information. With an EPSS score of 0.54165, there is a high probability of this flaw being exploited. This vulnerability is also in CISA's KEV catalog, highlighting its active exploitation and critical nature.

This vulnerability is actively being exploited in the wild and is listed in CISA's Known Exploited Vulnerabilities catalog. Exploitation occurs when secure functions are called under the non-secure processing environment handler mode.

Recommended Action

Yealink Device Management server administrators should apply the latest security updates to address this vulnerability. Implement robust access controls and monitor for unusual activity related to secure function calls.

Generated by the CTIWATCH analysis pipeline from this CVE's metadata (CVSS, EPSS, KEV status, exploit intelligence). Verify against vendor advisories before acting.

Technical Analysis

CVE-2021-27562 requires local access, meaning attackers must already have a foothold on the target system.

Exploitation requires some privileges, which limits the exposure to scenarios where an attacker has already gained initial access.

CISA has added CVE-2021-27562 to the Known Exploited Vulnerabilities (KEV) catalog, confirming active exploitation in the wild. U.S. federal agencies are required to patch this within the mandated timeframe, and all organizations should treat remediation as urgent.