CVE-2025-20248
BaseFortify
Publication date: 2025-09-10
Last updated on: 2025-09-11
Assigner: Cisco Systems, Inc.
Description
Description
CVSS Scores
EPSS Scores
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Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| cisco | ncs_5700 | * |
| cisco | ios_xr_software | * |
| cisco | iosxr_white_box | * |
| cisco | ios_xrv_9000_routers | * |
| cisco | asr_9000_series_routers | * |
| cisco | ncs_540 | * |
| cisco | ncs_5000 | * |
| cisco | ncs_1000 | * |
| cisco | ncs_6000 | * |
| cisco | ncs_5500 | * |
| cisco | ncs_560 | * |
Helpful Resources
Exploitability
| CWE ID | Description |
|---|---|
| CWE-347 | The product does not verify, or incorrectly verifies, the cryptographic signature for data. |
Attack-Flow Graph
AI Powered Q&A
Can you explain this vulnerability to me?
This vulnerability in Cisco IOS XR Software allows an authenticated local attacker with root-system privileges to bypass the software image signature verification during installation. It occurs because of incomplete validation of files within an .iso installation image, enabling the attacker to modify the .iso contents and install and activate unsigned software on affected devices. [1]
How can this vulnerability impact me? :
If exploited, this vulnerability could allow an attacker with root access to load and activate unsigned, potentially malicious software on the device. This could compromise the device's confidentiality and integrity, leading to unauthorized control or manipulation of the system. However, exploitation requires already having root-system privileges. [1]
How can this vulnerability be detected on my network or system? Can you suggest some commands?
This vulnerability can be detected by verifying the integrity of the Cisco IOS XR Software image installed on the device. You should compare the MD5 or SHA512 checksums of the installed image against the official checksums published on Cisco.com. Monitoring devices for unexpected downgrades to vulnerable software versions is also recommended. Specific commands to perform checksum validation are demonstrated in the Cisco advisory, typically involving commands to display the image checksum on the device and comparing it to the published values. [1]
What immediate steps should I take to mitigate this vulnerability?
Immediate mitigation steps include upgrading affected devices to the fixed Cisco IOS XR Software releases. The first fixed releases are IOS XR 24.2.21 and 24.4.2; versions 25.1 and later are not affected. Since no workarounds exist, applying these updates is critical. Additionally, ensure that you verify software image integrity before installation by checking MD5 or SHA512 checksums. Monitor devices for any unexpected downgrades to vulnerable versions. If you do not have a service contract, contact Cisco TAC with proof of entitlement to obtain the fixes. [1]