How severe is CVE-2020-3524?

CVE-2020-3524 has a CVSS 3.x base score of 6.8, rated medium severity. It is exploitable over physical access with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2020-3524 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (20th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2020-3524?

CVE-2020-3524 affects Cisco Ios Xe Rom Monitor. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2020-3524?

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

When was CVE-2020-3524 published?

CVE-2020-3524 was published on 2020-09-24 and last updated on 2026-06-17.

CVE-2020-3524

CVE-2020-3524 is a medium-severity vulnerability in Cisco Ios Xe Rom Monitor with a CVSS 3.x base score of 6.8. 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-862.

Key facts

Severity: Medium (CVSS 3.x base score 6.8)
CVSS v2: 6.9
EPSS exploit prediction: 0% (20th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-862
Affected product: Cisco Ios Xe Rom Monitor
Published: 2020-09-24
Last modified: 2026-06-17

Description

A vulnerability in the Cisco IOS XE ROM Monitor (ROMMON) Software for Cisco 4000 Series Integrated Services Routers, Cisco ASR 920 Series Aggregation Services Routers, Cisco ASR 1000 Series Aggregation Services Routers, and Cisco cBR-8 Converged Broadband Routers could allow an unauthenticated, physical attacker to break the chain of trust and load a compromised software image on an affected device. The vulnerability is due to the presence of a debugging configuration option in the affected software. An attacker could exploit this vulnerability by connecting to an affected device through the console, forcing the device into ROMMON mode, and writing a malicious pattern using that specific option on the device. A successful exploit could allow the attacker to break the chain of trust and load a compromised software image on the affected device. A compromised software image is any software image that has not been digitally signed by Cisco.

Frequently asked questions

What is CVE-2020-3524?: A vulnerability in the Cisco IOS XE ROM Monitor (ROMMON) Software for Cisco 4000 Series Integrated Services Routers, Cisco ASR 920 Series Aggregation Services Routers, Cisco ASR 1000 Series Aggregation Services Routers, and Cisco cBR-8 Converged Broadband Routers could allow an unauthenticated, physical attacker to break the chain of trust and load a compromised software image on an affected device. The vulnerability is due to the presence of a debugging configuration option in the affected software. An attacker could exploit this vulnerability by connecting to an affected device through the console, forcing the device into ROMMON mode, and writing a malicious pattern using that specific option on the device. A successful exploit could allow the attacker to break the chain of trust and load a compromised software image on the affected device. A compromised software image is any software image that has not been digitally signed by Cisco.
How severe is CVE-2020-3524?: CVE-2020-3524 has a CVSS 3.x base score of 6.8, rated medium severity. It is exploitable over physical access with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2020-3524 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (20th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2020-3524?: CVE-2020-3524 affects Cisco Ios Xe Rom Monitor. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2020-3524?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2020-3524 published?: CVE-2020-3524 was published on 2020-09-24 and last updated on 2026-06-17.

References

https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-rommon-secboot-7JgVLVYC

Affected products (1)

cpe:2.3:o:cisco:ios_xe_rom_monitor:*:*:*:*:*:*:*:*

More vulnerabilities in Cisco Ios Xe Rom Monitor

CVE-2021-1452 — Medium (CVSS 6.8): A vulnerability in the ROM Monitor (ROMMON) of Cisco IOS XE Software for Cisco Catalyst IE3200, IE3300, and IE3400…
CVE-2022-20864 — Medium (CVSS 4.6): A vulnerability in the password-recovery disable feature of Cisco IOS XE ROM Monitor (ROMMON) Software for Cisco…

All CVEs affecting Cisco Ios Xe Rom Monitor →

Other CWE-862 (Missing Authorization) vulnerabilities

CVE-2026-0092 — Critical (CVSS 10.0): In Package Manager, there is a possible device lock controller bypass due to a missing permission check. This could…
CVE-2026-33712 — Critical (CVSS 10.0): Typebot is a chatbot builder tool. In versions 3.15.2 and prior, the preview chat endpoint (POST…
CVE-2026-2031 — Critical (CVSS 10.0): An Improper Access Control vulnerability in several internal API endpoints for Google Cloud Application Integration…
CVE-2026-34976 — Critical (CVSS 10.0): Dgraph is an open source distributed GraphQL database. Prior to 25.3.1, the restoreTenant admin mutation is missing…
CVE-2025-30416 — Critical (CVSS 10.0): Sensitive data disclosure and manipulation due to missing authorization. The following products are affected: Acronis…
CVE-2025-45854 — Critical (CVSS 10.0): /server/executeExec of JEHC-BPM 2.0.1 allows attackers to execute arbitrary code via execParams.

Browse all CWE-862 (Missing Authorization) vulnerabilities →