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Fencer Intel
medium 4.9

CVE-2020-3308 json

Cisco Firepower Threat Defense Software Signature Verification Bypass Vulnerability

published 6y ago modified 2mo ago also EUVD-2020-24579

cvss
4.9
version 3.0, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.6%
EPSS 0.6% chance of exploitation in 30 days, percentile 49%
public exploits
0
none known

Summary

A vulnerability in the Image Signature Verification feature of Cisco Firepower Threat Defense (FTD) Software could allow an authenticated, remote attacker with administrator-level credentials to install a malicious software patch on an affected device. The vulnerability is due to improper verification of digital signatures for patch images. An attacker could exploit this vulnerability by crafting an unsigned software patch to bypass signature checks and loading it on an affected device. A successful exploit could allow the attacker to boot a malicious software patch image.

Patch / fix

  • cisco secure_firewall_threat_defense 6.2.2.1

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CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
last yr.

Exploit prediction

0.61% chance of exploitation in the next 30 days, higher than 49% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by version score vector
CNA 3.0 4.9 CVSS:3.0/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:H/A:N
NVD 3.1 4.9 CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:H/A:N
NVD 2.0 4.0 AV:N/AC:L/Au:S/C:N/I:P/A:N

Affected products

  • Cisco Cisco Firepower Threat Defense Software

Classification

Weakness
  • CWE-347 Improper Verification of Cryptographic Signature

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.