CVE-2020-3179Network attack vector

Device crash via GRE-over-IPv6 double free

Published May 6, 2020 · Updated Nov 15, 2024

Double-free in Cisco Firepower Threat Defense 6.3.0 and 6.4.0 allows remote attackers to crash devices via crafted GRE-over-IPv6 packets. The LINA engine GRE tunnel decapsulation path releases memory twice while processing IPv4 or IPv6 payloads carried in GRE over IPv6. The feature is enabled by default and cannot be disabled, so traffic traversing an affected device can crash it without exposing or changing data.

CVSS severity8.6
High
EPSS probability1.93%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Double-free in Cisco Firepower Threat Defense 6.3.0 and 6.4.0 allows remote attackers to crash devices via crafted GRE-over-IPv6 packets. The LINA engine GRE tunnel decapsulation path releases memory twice while processing IPv4 or IPv6 payloads carried in GRE over IPv6. The feature is enabled by default and cannot be disabled, so traffic traversing an affected device can crash it without exposing or changing data.

The record

CVE
CVE-2020-3179
Published
May 6, 2020
Updated
Nov 15, 2024
Vendor
ClamAV
Product
Cisco Firepower Threat Defense
Classifications
CWE-415, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 6, 2020CVE publishedPublication date reported by the CVE source.
  2. Nov 15, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=n/a

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

ClamAV · Cisco Firepower Threat Defenseversion=n/a

Published CVSS scores

8.6Cisco Systems, Inc.CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H/E:X/RL:X/RC:X
7.5NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
7.8NIST NVDAV:N/AC:L/Au:N/C:N/I:N/A:C

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-415Double Free
T1499.004Endpoint Denial of Service: Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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