CVE-2020-10136: CVE-2020-10136: IP-in-IP protocol specifies IP Encapsulation within IP standard (RFC 2003, STD 1) that dec…
cisco · nx-os · NVD published 2020-06-02 · posted 2025-01-21 · last modified 2026-06-17
What it is
IP-in-IP protocol specifies IP Encapsulation within IP standard (RFC 2003, STD 1) that decapsulate and route IP-in-IP traffic is vulnerable to spoofing, access-control bypass and other unexpected behavior due to the lack of validation to verify network packets before decapsulation and routing.
| Weakness | CWE-290 |
|---|---|
| CVSS vector | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L (source: [email protected]) |
| ATT&CK tactics | Initial Access → Persistence → Privilege Escalation → Stealth |
Exploitation evidence
First exploit evidence seen: 2025-01-21 (earliest date across the sources below).
Exploited in the wild
No source on this site lists in-the-wild exploitation yet (CISA KEV, VulnCheck KEV).
Public exploit code
GitHub proof-of-concept repositories
1 public repositories from 1 accounts, first seen 2025-01-21. Most starred: PapayaJackal/ipeeyoupeewepee (12 stars), view repository.
Verify before running: public PoCs can be malicious. Read the code and only run it in an isolated lab. A PoC means exploit code is public, not that this CVE is exploited in the wild.
Sources: nomi-sec/PoC-in-GitHub.
How to fix it
Fixed versions
- digi saros: upgrade to 8.1.0.1 or later
- hp x3220nr firmware: upgrade to 3.00.11.08 or later
- treck tcp\/ip: upgrade to 6.0.1.67 or later
Derived from the NVD CPE configuration (versionEndExcluding / versionEndIncluding). Always confirm with the vendor advisory.
Vendor advisories and patches
- https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-nxos-ipip-dos-kCT9X4 (Vendor Advisory)
MITRE ATT&CK mitigations for this chain
- M1048 Application Isolation and Sandboxing (for T1190) : Application isolation will limit what other processes and system features the exploited target can access.
- M1037 Filter Network Traffic (for T1190) : Restrict outbound network traffic from public-facing servers to prevent unauthorized connections from initiating communications with attacker-controlled infrastructure. While this may not prevent the initial exploitation, it limits the attacker's ability to verify and control the compromised server post-exploit, reduci
- M1030 Network Segmentation (for T1190) : Segment externally facing servers and services from the rest of the network with a DMZ or on separate hosting infrastructure.
- M1016 Vulnerability Scanning (for T1190) : Regularly scan externally facing systems for vulnerabilities and establish procedures to rapidly patch systems when critical vulnerabilities are discovered through scanning and through public disclosure.
- M1026 Privileged Account Management (for T1190, T1078) : Use least privilege for service accounts will limit what permissions the exploited process gets on the rest of the system.
- M1050 Exploit Protection (for T1190) : Web Application Firewalls may be used to limit exposure of applications to prevent exploit traffic from reaching the application.
- M1035 Limit Access to Resource Over Network (for T1190) : Ensure that all publicly exposed services are actually intended to be so, and restrict access to any that should only be available internally.
- M1051 Update Software (for T1190) : Update software regularly by employing patch management for externally exposed applications.
- M1027 Password Policies (for T1078) : Applications and appliances that utilize default username and password should be changed immediately after the installation, and before deployment to a production environment. When possible, applications that use SSH keys should be updated periodically and properly secured. Policies should minimize (if not eliminate)
- M1018 User Account Management (for T1078) : Regularly audit user accounts for activity and deactivate or remove any that are no longer needed.
Detection Generic guidance
- Initial Access: Alert on unusual requests to the affected service (odd paths, oversized payloads, exploit strings) in WAF, reverse-proxy and application logs.
- Persistence: Look for new files in web roots, new scheduled tasks/services, and new accounts created after the exposure window.
- Privilege Escalation: Alert on processes gaining SYSTEM/root unexpectedly, and on exploitation crashes of privileged services.
Response checklist Generic guidance
- Inventory: find every instance of the affected product and version (include internet-facing and forgotten ones).
- Patch or mitigate per the vendor advisory; if you cannot patch, remove internet exposure or apply the vendor workaround.
- Assume compromise if the system was exposed before patching: hunt for the indicators in the advisory and review logs back to the disclosure date.
- Rotate credentials and secrets stored on or used by the affected system if compromise cannot be ruled out.
Sources
- NVD: CVE-2020-10136
- CVE.org record
- FIRST EPSS (2026-10-24)
- https://datatracker.ietf.org/doc/html/rfc6169
- https://kb.cert.org/vuls/id/636397/ (Third Party Advisory, US Government Resource)
- https://www.digi.com/resources/security (Third Party Advisory)
- https://www.kb.cert.org/vuls/id/636397 (Third Party Advisory, US Government Resource)
- https://www.kb.cert.org/vuls/id/199397