CVE-2020-3524
Cisco IOS XE ROM Monitor Software Vulnerability
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.
Attack profile
How easy it is to exploit
- Attack vector
- Physical
- Complexity
- High
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Exploit likelihood
What each source reports
CVE List Score used
6.4
Cisco IOS XE ROM Monitor Software Vulnerability
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.
- Record
CVE-2020-3524- CVSS 3.0
- 6.4 Medium
CVSS:3.0/AV:P/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H - Weakness
- CWE-284
- Updated
- 2026-11-02
EUVDEUVD-2020-24795
6.4
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.
- Record
EUVD-2020-24795- CVSS 3.0
- 6.4 Medium
CVSS:3.0/AV:P/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H - Updated
- 2026-11-03
GitHub AdvisoriesGHSA-wvf6-cqwc-cf6x
6.8
A vulnerability in the Cisco IOS XE ROM Monitor (ROMMON) Software for Cisco 4000 Series...
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.
- Record
GHSA-wvf6-cqwc-cf6x- CVSS 3.1
- 6.8 Medium
CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - Weakness
- CWE-284, CWE-862
- Updated
- 2026-11-02
NVD
6.8
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.
- Record
CVE-2020-3524- CVSS 3.1
- 6.8 Medium
CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - CVSS 3.0
- 6.4 Medium
CVSS:3.0/AV:P/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H - CVSS 2.0
- 6.9 Medium
AV:L/AC:M/Au:N/C:C/I:C/A:C - Weakness
- CWE-284, CWE-862
- Updated
- 2026-11-02
Affected products
History
| Recorded | Changed | Sources |
|---|---|---|
| aliases, published | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2020-3524 is a medium vulnerability (CVSS 6.4) in Cisco Ios Xe Rom Monitor, published September 24, 2020. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.29%, the 21st percentile. No source names a fixed version.