Known exploited · Cisco
CVE-2016-6415: Cisco IOS, IOS XR, and IOS XE IKEv1 Information Disclosure Vulnerability
What it is
Cisco IOS, IOS XR, and IOS XE contain insufficient condition checks in the part of the code that handles Internet Key Exchange version 1 (IKEv1) security negotiation requests. contains an information disclosure vulnerability in the Internet Key Exchange version 1 (IKEv1) that could allow an attacker to retrieve memory contents. Successful exploitation could allow the attacker to retrieve memory contents, which can lead to information disclosure.
- Vendor
- Cisco
- Product
- IOS, IOS XR, and IOS XE
- Added to KEV
- May 19, 2023
- CISA due date
- June 9, 2023
- Ransomware use
- Unknown
What CISA requires
Apply updates per vendor instructions.
Forensic triage
No
What to do now
- Find every instance of IOS, IOS XR, and IOS XE you run, including the forgotten ones, and check its version against the vendor advisory.
- Apply the vendor's fix or mitigation, before June 9, 2023 if you are bound by CISA's deadline, sooner if it faces the internet.
- Assume it was tried against you already: look for signs of exploitation from the date it was added, not from the day you patched.
References
H2 Security
Not sure you are clear?
We check where you run it, patch or mitigate with your team, and look for signs it was already used against you.
Talk to our teamT Academy
Train the engineers who fix it
Security engineering on real hosts in the browser, every objective checked on the machine. The first two lessons of Linux 1 are free.
Start freeSource: CISA Known Exploited Vulnerabilities Catalog (public domain), catalog version 2026.10.01.