CVE-2020-3516

mediumpriority · track · 18EPSS 0.017 · 77 %ileEURUUS
grimoire priorityP3 · Track
Exploitable?
—
no known exploitation
Likely / severe?
1.67% (77th) EPSS
CVSS 4 · medium
Is it mine?
100 products
Check your exposure
Who says so?
5 sources
cnnvd · enisa_euvd · fstec_bdu · cisa_csaf_ot

EPSS · scored 2026-10-27

A vulnerability in the web server authentication of Cisco IOS XE Software could allow an authenticated, remote attacker to crash the web server on the device. The vulnerability is due to insufficient input validation during authentication. An attacker could exploit this vulnerability by entering unexpected characters during a valid authentication. A successful exploit could allow the attacker to crash the web server on the device, which must be manually recovered by disabling and re-enabling the web server.

01

remediations

Vendor fix, mitigation, or workaround guidance, as published by each source.

A vendor fix is available.

02

cvss

Technical severity, 0–10. One row per scoring source.

4.3
010

base score 0–10 · higher = more severe · hover a vector to decode

v2.04mediumAV:N/AC:L/Au:S/C:N/I:N/A:Pprimary · NVD / NIST USexploitability 8 · impact 2.9
v3.14.3mediumCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:Lprimary · NVD / NIST USexploitability 2.8 · impact 1.4
v3.04.3mediumCVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:Lsecondary · ENISA EU
v3.04.3mediumCVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:Lsecondary · psirt@cisco.com USexploitability 2.8 · impact 1.4
v3.04.3mediumCVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:Lsecondary · Cisco PSIRT US
v3.04.3mediumCVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:Lsecondary · CISA US
v3.14mediumCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L/E:Usecondary · CVSS-BT (t0sche)
v3.14.3mediumAV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:Lsecondary · FSTEC (BDU) RU
03

ssvc

A stakeholder decision — act, attend, or track — from exploitation and impact.

Trackcoordinatorcisa_ssvcUS
04

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-20USprimaryCWE-20USCWE-20US
05

affected products (100)

Products and version ranges known to be affected.

showing 20 of 100
06

advisories (2)

Vendor and ecosystem advisories describing this.

  • cisco-sa-WEB-UI-exNFmcPOCisco IOS XE Software Web UI Improper Input Validation Vulnerability2020-09-24csaf · cisco_csafUS

    A vulnerability in the web server authentication of Cisco IOS XE Software could allow an authenticated, remote attacker to crash the web server on the device. The vulnerability is due to insufficient input validation during authentication. An attacker could exploit this vulnerability by entering unexpected characters during a valid authentication. A successful exploit could allow the attacker to crash the web server on the device, which must be manually recovered by disabling and re-enabling the web server. Cisco has released software updates that address this vulnerability. There are no workarounds that address this vulnerability.

  • ICSA-22-300-03Rockwell Automation Stratix Devices Containing Cisco IOS2022-10-27icsa · cisa_csaf_otUS

    Successful exploitation of these vulnerabilities could lead to a denial-of-service condition and allow remote code execution.

07

also known as (4)

Other names and identifiers for this entity.

08

sources

Which sources assert this record, and when.

cnnvdenisa_euvdfstec_bducisa_csaf_otcisco_csafNVDCVE.orgMITRE
published 2020-09-24modified 2026-06-17
10

references (8)

External citations — patches, advisories, analysis.

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