Cyber Resilience

CVE-2021-27459

Critical

Published: 20 May 2021

Published
20 May 2021
Modified
21 November 2024
KEV Added
Patch
CVSS Score v3.1 9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.0069 72.4th percentile
Risk Priority 20 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2021-27459 is a critical-severity Unrestricted Upload of File with Dangerous Type (CWE-434) vulnerability in Emerson X-Stream Enhanced Xegp Firmware. Its CVSS base score is 9.8 (Critical).

Operationally, ranked in the top 27.6% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.

EU & UK References

Vulnerability details

A vulnerability has been found in multiple revisions of Emerson Rosemount X-STREAM Gas Analyzer. The webserver of the affected products allows unvalidated files to be uploaded, which an attacker could utilize to execute arbitrary code.

CWE(s)

Related Threats

No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.

Affected Assets

emerson
x-stream enhanced xegp firmware
all versions
emerson
x-stream enhanced xegk firmware
all versions
emerson
x-stream enhanced xefd firmware
all versions
emerson
x-stream enhanced xexf firmware
all versions

Mitigating Controls

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

addresses: CWE-434

Requiring identifiable owners for portable devices reduces the attack surface for unrestricted uploads of dangerous file types via anonymous media.

addresses: CWE-434

Dangerous file uploads can be detonated in the chamber to determine malice before any production write or execution occurs.

addresses: CWE-434

Prevents unrestricted writing of arbitrary or malicious firmware by keeping hardware write-protect enabled except under tightly controlled manual procedures.

addresses: CWE-434

Scans files from external sources on download/open/execute, blocking unrestricted uploads of dangerous file types.

References