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Public proof of conceptFix available

CVE-2018-0101

A public proof of concept exists; no exploitation attested.

  • Published2018-01-29
  • Fixed in9.9.1.2 · 9.8.2.20 · 9.7.1.21 · 9.6.4.3 · 9.4.4.16 · 9.2.4.27
  • WeaknessCWE-415

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

Description

A vulnerability in the Secure Sockets Layer (SSL) VPN functionality of the Cisco Adaptive Security Appliance (ASA) Software could allow an unauthenticated, remote attacker to cause a reload of the affected system or to remotely execute code. The vulnerability is due to an attempt to double free a region of memory when the webvpn feature is enabled on the Cisco ASA device. An attacker could exploit this vulnerability by sending multiple, crafted XML packets to a webvpn-configured interface on the affected system. An exploit could allow the attacker to execute arbitrary code and obtain full control of the system, or cause a reload of the affected device. This vulnerability affects Cisco ASA Software that is running on the following Cisco products: 3000 Series Industrial Security Appliance (ISA), ASA 5500 Series Adaptive Security Appliances, ASA 5500-X Series Next-Generation Firewalls, ASA Services Module for Cisco Catalyst 6500 Series Switches and Cisco 7600 Series Routers, ASA 1000V Cloud Firewall, Adaptive Security Virtual Appliance (ASAv), Firepower 2100 Series Security Appliance, Firepower 4110 Security Appliance, Firepower 9300 ASA Security Module, Firepower Threat Defense Software (FTD). Cisco Bug IDs: CSCvg35618.

Timeline

dates in UTC
  1. 2018-01-2920:29CVE publishedNVD
  2. 2026-10-2319:23First public proof of conceptPoC-in-GitHub
  3. 2026-10-2319:23EPSS crossed 10 %FIRST EPSS

Observed activity

isMalicious corpus · updated 2026-10-23 18:48 UTC
Indicators tagged with this CVE, per day0 indicators over 7 days
Block these indicators
  • Firewall list (EDL, text): https://api.ismalicious.com/edl/cve/CVE-2018-0101?format=txt
  • CSV export: https://api.ismalicious.com/edl/cve/CVE-2018-0101?format=csv
  • TAXII collection of exploited CVEs
  • The EDL and CSV take an API key on the Pro plan.

Versions per branch

NVD
Cisco ASA
BranchAffectedFixed in
9.9≥ 9.9.0, < 9.9.1.29.9.1.2
9.8≥ 9.8.0, < 9.8.2.209.8.2.20
9.7≥ 9.7.0, < 9.7.1.219.7.1.21
9.x≥ 9.5.0, < 9.6.4.39.6.4.3
9.x≥ 9.3.0, < 9.4.4.169.4.4.16
9.2≥ 9.2.0, < 9.2.4.279.2.4.27
9.1< 9.1.7.239.1.7.23
Cisco secure firewall threat defense
BranchAffectedFixed in
6.0= 6.0.0no fix published
6.0= 6.0.1no fix published
6.1= 6.1.0no fix published
6.2= 6.2.0no fix published
6.2= 6.2.1no fix published
6.2= 6.2.2no fix published

as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.

Fix

  1. Update Cisco ASA to 9.9.1.2 · 9.8.2.20 · 9.7.1.21 · 9.6.4.3 · 9.4.4.16 · 9.2.4.27 · 9.1.7.23

Advisories and patches

Detection

read 2026-10-23 19:23 UTC
Nuclei template
none so far
ProjectDiscovery
Exploit-DB
no entry
Exploit-DB
Proof-of-concept repositories
2 repositories, unverified1337g/CVE-2018-0101-DOS-POCCymmetria/ciscoasa_honeypot
PoC-in-GitHub

Sources

  • CISA-ADPSSVC decisionnone2024-12-02
  • OpenCVESSVC decisionnone—
  • NVDCVSS 3.010read 2026-10-23
  • NVDCVSS 2.010read 2026-10-23
  • CNAweakness (CWE)CWE-415read 2026-10-23
  • NVDweakness (CWE)CWE-415read 2026-10-23
  • FIRST EPSSEPSS score86.8 %read 2026-10-23
  • PoC-in-GitHubproof of concept2read 2026-10-23

Technical details

CVSS v3 Vector
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
Published
2018-01-29
Last Modified
2026-08-11
NVD status
Modified

Frequently asked questions

What is CVE-2018-0101?

A vulnerability in the Secure Sockets Layer (SSL) VPN functionality of the Cisco Adaptive Security Appliance (ASA) Software could allow an unauthenticated, remote attacker to cause a reload of the affected system or to remotely execute code. The vulnerability is due to an attempt to double free a region of memory when the webvpn feature is enabled on the Cisco ASA device. An attacker could exploit this vulnerability by sending multiple, crafted XML packets to a webvpn-configured interface on the affected system. An exploit could allow the attacker to execute arbitrary code and obtain full control of the system, or cause a reload of the affected device. This vulnerability affects Cisco ASA Software that is running on the following Cisco products: 3000 Series Industrial Security Appliance (ISA), ASA 5500 Series Adaptive Security Appliances, ASA 5500-X Series Next-Generation Firewalls, ASA Services Module for Cisco Catalyst 6500 Series Switches and Cisco 7600 Series Routers, ASA 1000V Cloud Firewall, Adaptive Security Virtual Appliance (ASAv), Firepower 2100 Series Security Appliance, Firepower 4110 Security Appliance, Firepower 9300 ASA Security Module, Firepower Threat Defense Software (FTD). Cisco Bug IDs: CSCvg35618.

Is CVE-2018-0101 actively exploited?

Active exploitation of CVE-2018-0101 has not been confirmed. Its EPSS score was 86.8% on 2026-10-22, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2018-0101?

CVE-2018-0101 has a CVSS v3 base score of 10 (CRITICAL severity), with vector string CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H.

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