CVE-2023-20236

highpriority · track · 31OT risk · elevatedEPSS 0.001 · 1 %ileDEEURUUS
grimoire priorityP2 · Scheduled
Exploitable?
—
no known exploitation
Likely / severe?
0.10% (1st) EPSS
CVSS 7.8 · high
Is it mine?
90 products
Check your exposure
Who says so?
5 sources
cnnvd · enisa_euvd · fstec_bdu · cisco_csaf

EPSS · scored 2026-10-28

A vulnerability in the iPXE boot function of Cisco IOS XR software could allow an authenticated, local attacker to install an unverified software image on an affected device. This vulnerability is due to insufficient image verification. An attacker could exploit this vulnerability by manipulating the boot parameters for image verification during the iPXE boot process on an affected device. A successful exploit could allow the attacker to boot an unverified software image on the affected device.

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.

7.8
010

base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · medium–high · 6.7–7.8

v3.17.8highCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:Hprimary · NVD / NIST USexploitability 1.8 · impact 5.9
v3.16.7mediumAV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:Hsecondary · FSTEC (BDU) RU
v3.16.7mediumCVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:Hsecondary · ENISA EU
v3.16.7mediumCVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:Hsecondary · psirt@cisco.com USexploitability 0.8 · impact 5.9
v3.17.1highCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:Usecondary · CVSS-BT (t0sche)
v3.16.7mediumCVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:Hsecondary · Cisco PSIRT US
03

ssvc

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

Exploitation: none · Automatable: no · Technical Impact: totalcoordinatorcisa_ssvcUS
04

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-345USprimaryCWE-345USCWE-347US
05

affected products (90)

Products and version ranges known to be affected.

showing 20 of 90
06

advisories (2)

Vendor and ecosystem advisories describing this.

  • WID-SEC-W-2023-2355Cisco IOS XR: Mehrere SchwachstellenDeutsch2023-09-13csaf · cert_bundDE

    Ein Angreifer kann mehrere Schwachstellen in Cisco IOS XR ausnutzen, um beliebigen Code auszuführen, Sicherheitsmaßnahmen zu umgehen oder einen Denial-of-Service-Zustand zu verursachen.

  • cisco-sa-iosxr-ipxe-sigbypass-pymfyqgBCisco IOS XR Software iPXE Boot Signature Bypass Vulnerability2023-09-13csaf · cisco_csafUS

    A vulnerability in the iPXE boot function of Cisco IOS XR software could allow an authenticated, local attacker to install an unverified software image on an affected device. This vulnerability is due to insufficient image verification. An attacker could exploit this vulnerability by manipulating the boot parameters for image verification during the iPXE boot process on an affected device. A successful exploit could allow the attacker to boot an unverified software image on the affected device. Cisco has released software updates that address this vulnerability. There are no workarounds that address this vulnerability. This advisory is part of the September 2023 release of the Cisco IOS XR Software Security Advisory Bundled Publication. For a complete list of the advisories and links to them, see Cisco Event Response: September 2023 Semiannual Cisco IOS XR Software Security Advisory Bundled Publication ["https://sec.cloudapps.cisco.com/security/center/viewErp.x?alertId=ERP-75241"].

07

also known as (4)

Other names and identifiers for this entity.

08

sources

Which sources assert this record, and when.

cnnvdenisa_euvdfstec_bducisco_csafcert_bundNVDCVE.orgMITRE
published 2023-09-13modified 2026-06-17
10

references (5)

External citations — patches, advisories, analysis.

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