CVE-2020-3203Network attack vector

Remote device crash via crafted SSL packets

Published Jun 3, 2020 · Updated Nov 15, 2024

Resource exhaustion in Cisco IOS XE on Catalyst 9800 controllers allows remote attackers to crash devices with crafted SSL packets. The LSC provisioning feature incorrectly processes PKI data in the packets and continuously consumes memory until allocation failure. The unauthenticated network path is exposed only on controllers running an affected IOS XE release with locally significant certificates configured.

CVSS severity8.6
High
EPSS probability0.84%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Resource exhaustion in Cisco IOS XE on Catalyst 9800 controllers allows remote attackers to crash devices with crafted SSL packets. The LSC provisioning feature incorrectly processes PKI data in the packets and continuously consumes memory until allocation failure. The unauthenticated network path is exposed only on controllers running an affected IOS XE release with locally significant certificates configured.

The record

CVE
CVE-2020-3203
Published
Jun 3, 2020
Updated
Nov 15, 2024
Vendor
ClamAV
Product
Cisco IOS XE Software
Classifications
CWE-400, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 3, 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 IOS XE Softwareversion=n/a

Published CVSS scores

8.6CiscoCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H/E:X/RL:X/RC:X
8.6NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
7.8NVDAV: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.

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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-400Uncontrolled Resource Consumption
T1499.004Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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