CVE-2020-10136

IP-in-IP protocol allows a remote, unauthenticated attacker to route arbitrary network traffic

Description

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.

Remediation

Solution:

  • Customers should apply the latest patch provided by the affected vendor that addresses this issue and prevents unspecified IP-in-IP packets from being processed. Devices manufacturers are urged to disable IP-in-IP in their default configuration and require their customers to explicitly configure IP-in-IP as and when needed.

Workaround:

  • Users can block IP-in-IP packets by filtering IP protocol number 4. Note this filtering is for the IPv4 Protocol (or IPv6 Next Header) field value of 4 and not IP protocol version 4 (IPv4).

Category

5.3
CVSS
Severity: Medium
CVSS 3.1 •
CVSS 2.0 •
EPSS 15.92% Top 10%
Vendor Advisory cisco.com
Affected: IETF RFC2003 - IP Encapsulation within IP
Published at:
Updated at:

References

Link Tags
https://kb.cert.org/vuls/id/636397/ third party advisory us government resource
https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-nxos-ipip-dos-kCT9X4 vendor advisory
https://www.digi.com/resources/security third party advisory
https://www.kb.cert.org/vuls/id/636397 third party advisory us government resource
https://datatracker.ietf.org/doc/html/rfc6169

Frequently Asked Questions

What is the severity of CVE-2020-10136?
CVE-2020-10136 has been scored as a medium severity vulnerability.
How to fix CVE-2020-10136?
To fix CVE-2020-10136: Customers should apply the latest patch provided by the affected vendor that addresses this issue and prevents unspecified IP-in-IP packets from being processed. Devices manufacturers are urged to disable IP-in-IP in their default configuration and require their customers to explicitly configure IP-in-IP as and when needed.
Is CVE-2020-10136 being actively exploited in the wild?
It is possible that CVE-2020-10136 is being exploited or will be exploited in a near future based on public information. According to its EPSS score, there is a ~16% probability that this vulnerability will be exploited by malicious actors in the next 30 days.
What software or system is affected by CVE-2020-10136?
CVE-2020-10136 affects IETF RFC2003 - IP Encapsulation within IP.
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