CVE-2021-34709

Cisco IOS XR Software for Cisco 8000 and Network Convergence System 540 Series Routers Image Verification Vulnerabilities

MEDIUM

6.4

CVSS Score

Published: September 9, 2021 at 05:00 AM UTC

Updated: June 17, 2026 at 03:56 AM UTC

23 products affected across 1 vendorIOS Xr82018202

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Severity

MEDIUM6.4

Exploit prediction

EPSS 0.2%

SSVC

No known exploit

Description

Multiple vulnerabilities in image verification checks of Cisco Network Convergence System (NCS) 540 Series Routers, only when running Cisco IOS XR NCS540L software images, and Cisco IOS XR Software for Cisco 8000 Series Routers could allow an authenticated, local attacker to execute arbitrary code on the underlying operating system. For more information about these vulnerabilities, see the Details section of this advisory.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

IOS Xr · Cisco

95%

v < 7.3.27.4.0 ≤ v < 7.4.1

Affected range stops below 7.3.2, so it looks safe — our inference, not a vendor statement

Affected range stops below 7.4.1, so it looks safe — our inference, not a vendor statement

cisco-8101-32fh (environment) · cisco-8101-32h (environment) · cisco-8102-64h (environment) · cisco-8201 (environment) · cisco-8201-32fh (environment) · cisco-8202 (environment) · cisco-8800-12-slot (environment) · cisco-8800-18-slot (environment) · cisco-8800-4-slot (environment) · cisco-8800-8-slot (environment) · cisco-n540-12z20g-sys-a (environment) · cisco-n540-12z20g-sys-d (environment) · cisco-n540-24z8q2c-m (environment) · cisco-n540-24z8q2c-sys (environment) · cisco-n540-28z4c-sys-a (environment) · cisco-n540-28z4c-sys-d (environment) · cisco-n540-acc-sys (environment) · cisco-n540x-12z16g-sys-a (environment) · cisco-n540x-12z16g-sys-d (environment) · cisco-n540x-16z4g8q2c-a (environment) · cisco-n540x-16z4g8q2c-d (environment) · cisco-n540x-acc-sys (environment)

8101-32Fh · Ciscodevice

80%

All versions

8101-32H · Ciscodevice

80%

All versions

8102-64H · Ciscodevice

80%

All versions

8201 · Ciscodevice

80%

All versions