How severe is CVE-2023-20236?

CVE-2023-20236 has a CVSS 3.x base score of 6.7, rated medium severity. It is exploitable over local access with low attack complexity, requires high privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2023-20236 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (1st percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2023-20236?

CVE-2023-20236 affects Cisco Ios Xr. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2023-20236?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2023-20236 published?

CVE-2023-20236 was published on 2023-09-13 and last updated on 2026-06-17.

CVE-2023-20236

CVE-2023-20236 is a medium-severity vulnerability in Cisco Ios Xr with a CVSS 3.x base score of 6.7. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-345.

Key facts

Severity: Medium (CVSS 3.x base score 6.7)
EPSS exploit prediction: 0% (1st percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-345
Affected product: Cisco Ios Xr
Published: 2023-09-13
Last modified: 2026-06-17

Description

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.

Frequently asked questions

What is CVE-2023-20236?: 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.
How severe is CVE-2023-20236?: CVE-2023-20236 has a CVSS 3.x base score of 6.7, rated medium severity. It is exploitable over local access with low attack complexity, requires high privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2023-20236 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (1st percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2023-20236?: CVE-2023-20236 affects Cisco Ios Xr. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2023-20236?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2023-20236 published?: CVE-2023-20236 was published on 2023-09-13 and last updated on 2026-06-17.

References

https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-iosxr-ipxe-sigbypass-pymfyqgB

Affected products (1)

cpe:2.3:o:cisco:ios_xr:*:*:*:*:*:*:*:*

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