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Fencer Intel
medium 6.8

CVE-2020-3209 json

Cisco IOS XE Software Digital Signature Verification Bypass Vulnerability

published 6y ago modified 4mo ago also EUVD-2020-24480

cvss
6.8
version 3.0, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.3%
EPSS 0.3% chance of exploitation in 30 days, percentile 20%
public exploits
0
none known

Summary

A vulnerability in software image verification in Cisco IOS XE Software could allow an unauthenticated, physical attacker to install and boot a malicious software image or execute unsigned binaries on an affected device. The vulnerability is due to an improper check on the area of code that manages the verification of the digital signatures of system image files during the initial boot process. An attacker could exploit this vulnerability by loading unsigned software on an affected device. A successful exploit could allow the attacker to install and boot a malicious software image or execute unsigned binaries on the targeted device.

Patch / fix

Is CVE-2020-3209 in your stack? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

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Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

cisa ICSA-22-300-03 updated cvss 6.8

Rockwell Automation Stratix Devices Containing Cisco IOS

  • Rockwell Automation Stratix Devices <16.12.01
    affected: mitigation “Rockwell Automation has addressed these vulnerabilities updates and encourages users to combine these updates with Rockwell Automation's Security Best Practices:” rockwellautomation.custhelp.com

From CISA ICS and IT advisories (CSAF, https://github.com/cisagov/CSAF), a U.S. Government work; changed: reduced to products, statuses and remediations. CISA notification · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
total
Assessed
last yr.

Exploit prediction

0.28% chance of exploitation in the next 30 days, higher than 20% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by version score vector
CNA 3.0 6.8 CVSS:3.0/AV:P/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
NVD 3.1 6.8 CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
NVD 2.0 7.2 AV:L/AC:L/Au:N/C:C/I:C/A:C

Affected products

  • Cisco Cisco IOS XE Software 3.2.0SG

Classification

Weakness
  • CWE-347 Improper Verification of Cryptographic Signature
Technology feeds

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.