Format string error in Cisco Systems, Inc products - CVE-2020-3118
Published: February 7, 2020 / Updated: February 20, 2022
Vulnerability identifier: #VU25028
CSH Severity: Low
CVSS v4: 8.7 [CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2020-3118
CWE-ID: CWE-134
Exploitation vector: Adjecent network
Exploit availability:
The vulnerability is being exploited in the wild
Vulnerability details
The vulnerability allows a remote attacker to execute arbitrary code on the target system.
The vulnerability exists due to improper validation of string input from certain fields in the Cisco Discovery Protocol implementation for Cisco IOS XR Software. A remote attacker on the local network can supply a specially crafted input that contains format string specifiers, cause a stack overflow and execute arbitrary code with administrative privileges on an affected device.
Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.
Affected software
Cisco ASR 9000 Series Aggregation Services Routers
Cisco Network Convergence System 6000 Series Routers
Cisco IOS XRv 9000 Router
Cisco Network Convergence System 560 Series Routers
Cisco Network Convergence System 5000 Series
Cisco Network Convergence System 540 Series Routers
Network Convergence System 5500 Series
Cisco Carrier Routing System
Cisco Network Convergence System 1000 Series
Cisco Network Convergence System 6000 Series Routers
Cisco IOS XRv 9000 Router
Cisco Network Convergence System 560 Series Routers
Cisco Network Convergence System 5000 Series
Cisco Network Convergence System 540 Series Routers
Network Convergence System 5500 Series
Cisco Carrier Routing System
Cisco Network Convergence System 1000 Series
How to mitigate CVE-2020-3118
Install updates from vendor's website.
| Cisco IOS XR Software Release | First Fixed Release for This Vulnerability |
|---|---|
| Earlier than 6.6 | Appropriate SMU |
| 6.61 | 6.6.3 or appropriate SMU |
| 7.0 | 7.0.2 (Mar 2020) or appropriate SMU |
| 7.1 | Not vulnerable |
| Cisco IOS XR Software Release | Platform | SMU Name |
|---|---|---|
| 5.2.5 | NCS6K | ncs6k-5.2.5.CSCvr78185 |
| 6.4.2 | ASR9K-PX | asr9k-px-6.4.2.CSCvr78185 |
| CRS-PX | hfr-px-6.4.2.CSCvr78185 | |
| 6.5.3 | ASR9K-PX | asr9k-px-6.5.3.CSCvr78185 |
| ASR9K-X64 | asr9k-x64-6.5.3.CSCvr78185 | |
| NCS540 | ncs540-6.5.3.CSCvr78185 | |
| NCS5K | ncs5k-6.5.3.CSCvr78185 | |
| NCS5500 | ncs5500-6.5.3.CSCvr78185 | |
| XRV9K | xrv9k-6.5.3.CSCvr78185 | |
| 6.6.12 | White box | iosxrwbd-6.6.12.CSCvr78185 |
| 6.6.25 | NCS560 | ncs560-6.6.25.CSCvr78185 |
| 7.0.1 | NCS540L | ncs540l-7.0.1.CSCvr78185 |
Cisco ASR 9000 Series Aggregation Services Routers - update to 6.6.3
Cisco Carrier Routing System - update to 6.6.3
Cisco Network Convergence System 6000 Series Routers - update to 6.6.3
Cisco IOS XRv 9000 Router - update to 6.6.3
Cisco Network Convergence System 560 Series Routers - update to 6.6.3
Cisco Network Convergence System 5000 Series - update to 6.6.3
Cisco Network Convergence System 540 Series Routers - update to 6.6.3
Network Convergence System 5500 Series - update to 6.6.3
Cisco Network Convergence System 1000 Series - update to 6.6.3
Cisco Carrier Routing System - update to 6.6.3
Cisco Network Convergence System 6000 Series Routers - update to 6.6.3
Cisco IOS XRv 9000 Router - update to 6.6.3
Cisco Network Convergence System 560 Series Routers - update to 6.6.3
Cisco Network Convergence System 5000 Series - update to 6.6.3
Cisco Network Convergence System 540 Series Routers - update to 6.6.3
Network Convergence System 5500 Series - update to 6.6.3
Cisco Network Convergence System 1000 Series - update to 6.6.3