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Fencer Vulns
medium 4.0

CVE-2023-20070 json

A vulnerability in the TLS 1.3 implementation of the Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote a…

published 2023-11-01 3 y ago modified 2026-08-11 2 mo ago also EUVD-2023-24249

cvss
4.0
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.7%
EPSS 0.7% chance of exploitation in 30 days, percentile 54%
public exploits
0
none known

Summary

A vulnerability in the TLS 1.3 implementation of the Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause the Snort 3 detection engine to unexpectedly restart. This vulnerability is due to a logic error in how memory allocations are handled during a TLS 1.3 session. Under specific, time-based constraints, an attacker could exploit this vulnerability by sending a crafted TLS 1.3 message sequence through an affected device. A successful exploit could allow the attacker to cause the Snort 3 detection engine to reload, resulting in a denial of service (DoS) condition. While the Snort detection engine reloads, packets going through the FTD device that are sent to the Snort detection engine will be dropped. The Snort detection engine will restart automatically. No manual intervention is required.

Exploit prediction

0.72% chance of exploitation in the next 30 days, higher than 54% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 4.0 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:N/A:L
NVD 3.1 4.0 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:N/A:L

Affected products

  • Cisco Cisco Firepower Threat Defense Software

Classification

Weakness
  • CWE-244 Improper Clearing of Heap Memory Before Release

References

Sources

Fencer Vulns 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.