CVE-2021-27562
Arm — Arm Trusted Firmware Out-of-Bounds Write Vulnerability
Arm · CWE-787 — Out-of-bounds write · in CISA KEV since 2021-11-03
EVRS 75 of 100 Urgent
Patch This Cycle
Rank 1,189 of 2,960 tracked
Raised to the floor for a confirmed exploited vulnerability.
Why it scores 75
Evidence available: 6 of 7 signalsListed in the CISA KEV catalog, and an EPSS probability of 0.031.
- CISA KEVApplied
- RansomwareDid not apply
- Vendor exploitationDid not apply
- EPSSApplied
- Microsoft Exploitability IndexNot applicable
- Pre-patch disclosureNo data
- KEV recencyDid not apply
- CVSSApplied
The band answers “how soon”, not “how bad”. No data for: Pre-patch disclosure. Why some signals show no data
Fix
Patch or fixed version identifiedCISA required action
Fixed in
trusted firmware-m: update to a version newer than 1.2.0
Affected versions
- trusted firmware-m
<= 1.2.0
Remediation
Apply updates per vendor instructions.
Fixed versions from NVD.
Evidence
Each value with its source| Measure | Value | Source |
|---|---|---|
| CVSS base scoreHow severe the flaw is in itself. It does not say how likely an attack is. | 5.5 | NVD |
| FIRST EPSSFIRST's estimate of the chance this is exploited in the next 30 days, and how that ranks against all CVEs. | 0.031 (87.5th pctl) | FIRST EPSS |
| Actively exploitedWhether a source of record has confirmed attacks using it in the wild. | Confirmed | CISA KEV |
| Ransomware campaign useWhether CISA has seen ransomware operators use it. | Unknown or none | CISA KEV |
| CISA remediation deadlineThe date US federal agencies must have fixed or mitigated it. | 2021-11-17 · KEV since 2021 · listed over a year | CISA KEV |
| Public exploit moduleA module existing is not the same as active exploitation. | None known | Metasploit |
| EUVD cross-referenceENISA's record: CVSS 5.5 (v3.1), assigned by mitre. | Listed | ENISA EUVD |
Description
NVDIn Arm Trusted Firmware M through 1.2, the NS world may trigger a system halt, an overwrite of secure data, or the printing out of secure data when calling secure functions under the NSPE handler mode.
What CISA says to do
