Cisco Evolved Programmable Network Manager Arbitrary File Upload Vulnerability
TL;DR 📌
- A vulnerability in the web-based management interface of Cisco Evolved Programmable Network Manager (EPNM) could allow an authenticated, remote attacker to upload arbitrary files to an affected device. This vulnerability is due to improper validation of files that are uploaded to the web-based management interface. An attacker could exploit this vulnerability by sending a crafted…
- Highest CVSS: 4.3 (Medium).
- Check the advisory for fixed releases — remediation detail is in the vendor link below.
- CVEs: CVE-2025-20287.
What it is
CVE-2025-20287 is an arbitrary file upload vulnerability in the web-based management interface of Cisco Evolved Programmable Network Manager (EPNM). The flaw is due to improper validation of files submitted through a specific API endpoint on that interface.
Exploitation requires an authenticated remote attacker with at least valid Config Managers credentials on the affected device. There is no unauthenticated path here; the attacker needs to already hold a working account on the management plane before sending a crafted file upload request.
A successful upload lets the attacker place arbitrary files on the affected system. The advisory does not describe further impact such as code execution, so treat this as a file-placement primitive rather than a confirmed path to full compromise. Cisco’s own CVSS vector (AV:N/AC:L/PR:L/UI:N/C:N/I:L/A:N) reflects low integrity impact and no confidentiality or availability impact, consistent with the medium severity rating.
Cisco EPNM is affected regardless of device configuration — this isn’t tied to a particular feature being enabled.
What to do
- Upgrade EPNM 8.0 and earlier to release 8.1, which Cisco states is not vulnerable. There is no fixed release for 8.0 and earlier other than migrating to 8.1.
- There are no workarounds — patching is the only mitigation Cisco offers for this issue.
- Review who holds Config Managers credentials on EPNM instances; since exploitation requires that role, tightening account issuance and reviewing existing holders reduces exposure while you plan the upgrade.
- Confirm hardware and configuration compatibility with 8.1 before upgrading, or engage Cisco TAC if that’s unclear, as the advisory recommends.
For leadership 🧭
Executive summary. Any account with Config Managers rights on Cisco EPNM can be abused to write arbitrary files to the management server, and Cisco offers no workaround other than moving to release 8.1. This should be scheduled into the next maintenance window rather than treated as an emergency, given it needs an existing credential and the advisory describes no code execution path.
Why it matters:
- Exploitation requires only a valid Config Managers account on EPNM, not a privileged admin role, so the effective attacker population is anyone with that credential level, including compromised low-tier accounts.
- The flaw sits in the web-based management interface’s file upload handling on a specific API endpoint, meaning it’s reachable wherever that interface is exposed on the network.
- Cisco confirms EPNM is affected regardless of configuration, so there’s no feature to disable or setting to check as a stopgap — the only path is patching.
- The CVSS vector shows no confidentiality or availability impact, indicating this is a file-placement primitive rather than a demonstrated route to full system compromise, but it still weakens integrity of the management plane.
Now / Next / Later:
- Now: Identify all EPNM instances running 8.0 or earlier and list every account holding Config Managers credentials on them.
- Next: Upgrade affected EPNM instances to release 8.1 in the next change window, confirming hardware and configuration compatibility beforehand or engaging Cisco TAC if unclear.
- Later: Establish a periodic review of who is issued Config Managers credentials on EPNM, tightening issuance so the pool of accounts capable of triggering upload-based flaws stays minimal.