PT-2021-4141 · Cisco · Cisco Network Convergence System (Ncs) 540 Series Routers+2

Published 2021-09-08 · Updated 2021-09-21 · CVE-2021-34709

Positive Technologies (AI Summary)

CVSS v2.0

6.9

Medium

Base vector

AV:L/AC:M/Au:N/C:C/I:C/A:C

Name of the Vulnerable Software and Affected Versions Cisco IOS XR versions (affected versions not specified) Cisco Network Convergence System (NCS) 540 Series Routers running Cisco IOS XR NCS540L software images (affected versions not specified) Cisco IOS XR Software for Cisco 8000 Series Routers (affected versions not specified)

Description The issue is related to incorrect cryptographic signature verification in Cisco IOS XR, which could allow an authenticated, local attacker to execute arbitrary code on the underlying operating system.

Recommendations For Cisco IOS XR, update to a version that includes the software updates released by Cisco to address these vulnerabilities. For Cisco Network Convergence System (NCS) 540 Series Routers running Cisco IOS XR NCS540L software images, update to a version that includes the software updates released by Cisco to address these vulnerabilities. For Cisco IOS XR Software for Cisco 8000 Series Routers, update to a version that includes the software updates released by Cisco to address these vulnerabilities.

Fix

Improper Verification of Cryptographic Signature

Weakness Enumeration

CWE-347

Related Identifiers

BDU:2021-04734

CVE-2021-34709

Affected Products

Cisco 8000 Series Routers

Cisco Ios Xr

Cisco Network Convergence System (Ncs) 540 Series Routers

References · 6

• https://bdu.fstec.ru/vul/2021-04734 · Security Note
• https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-lnt-QN9mCzwn · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2021-34709 · Security Note
• https://osv.dev/vulnerability/CVE-2021-34709 · Vendor Advisory
• https://t.me/cibsecurity/28554 · Telegram Post
• https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-lnt-QN9mCzwn?vsfCisco20Security20AdvisoryvscatSecurity20IntelligencevstypeRSSvspCisco20IOS20XR20Software20for20Cisco20800020and20Network20Convergence20System2054020Series20Routers20Image20Verification20Vulnerabilitiesvsk1 · Note