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Fencer Intel
medium 6.8

CVE-2019-1687 json

Cisco Adaptive Security Appliance Software and Firepower Threat Defense Software TCP Proxy Denial of Service Vulnerability

published 7y ago modified 2mo ago also EUVD-2019-10244

cvss
6.8
version 3.0, CNA
cisa kev
Not listed
not in CISA's catalog
epss
2.9%
EPSS 2.9% chance of exploitation in 30 days, percentile 87%
public exploits
0
none known

Summary

A vulnerability in the TCP proxy functionality for Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause the device to restart unexpectedly, resulting in a denial of service (DoS) condition. The vulnerability is due to an error in TCP-based packet inspection, which could cause the TCP packet to have an invalid Layer 2 (L2)-formatted header. An attacker could exploit this vulnerability by sending a crafted TCP packet sequence to the targeted device. A successful exploit could allow the attacker to cause a DoS condition.

Patch / fix

  • Cisco Cisco Adaptive Security Appliance (ASA) Software 9.4.4.34, 9.8.4, 9.9.2.50

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CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
last yr.

Exploit prediction

2.93% chance of exploitation in the next 30 days, higher than 87% 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:N/AC:H/PR:N/UI:N/S:C/C:N/I:N/A:H
NVD 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
NVD 2.0 7.8 AV:N/AC:L/Au:N/C:N/I:N/A:C

Affected products

  • Cisco Cisco Adaptive Security Appliance (ASA) Software

Classification

Weakness
  • CWE-20 Improper Input Validation

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.