Known exploited vulnerability

CVE-2017-3881

criticalCVSS 3.1 9.8In CISA KEVEPSS 99%Published · n/a

The short answer

CVE-2017-3881 affects n/a Cisco IOS and IOS XE Software and is rated critical (CVSS 9.8). CISA added it to the Known Exploited Vulnerabilities catalog on 2022-03-25: attackers are using it, so patch it first.

What it is

A vulnerability in the Cisco Cluster Management Protocol (CMP) processing code in Cisco IOS and Cisco IOS XE Software could allow an unauthenticated, remote attacker to cause a reload of an affected device or remotely execute code with elevated privileges. The Cluster Management Protocol utilizes Telnet internally as a signaling and command protocol between cluster members. The vulnerability is due to the combination of two factors: (1) the failure to restrict the use of CMP-specific Telnet options only to internal, local communications between cluster members and instead accept and process such options over any Telnet connection to an affected device; and (2) the incorrect processing of malformed CMP-specific Telnet options. An attacker could exploit this vulnerability by sending malformed CMP-specific Telnet options while establishing a Telnet session with an affected Cisco device configured to accept Telnet connections. An exploit could allow an attacker to execute arbitrary code and obtain full control of the device or cause a reload of the affected device. This affects Catalyst switches, Embedded Service 2020 switches, Enhanced Layer 2 EtherSwitch Service Module, Enhanced Layer 2/3 EtherSwitch Service Module, Gigabit Ethernet Switch Module (CGESM) for HP, IE Industrial Ethernet switches, ME 4924-10GE switch, RF Gateway 10, and SM-X Layer 2/3 EtherSwitch Service Module. Cisco Bug IDs: CSCvd48893.

Weakness: CWE-20.

Severity

9.8 critical

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Exploited (CISA KEV)

Yes, since Mar 25, 2022

Federal due date Apr 15, 2022

EPSS, next 30 days

99%

Higher than 100% of scored CVEs

How it can be exploited

Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality impact
High
Integrity impact
High
Availability impact
High

What CISA says to do

Apply updates per vendor instructions.

Affected products

Cisco IOS and IOS XE Software. NVD's record lists the exact affected versions.

References

Questions

Is CVE-2017-3881 being exploited?

Yes. CISA added CVE-2017-3881 to its Known Exploited Vulnerabilities catalog on 2022-03-25, with a federal remediation due date of 2022-04-15.

How do I fix CVE-2017-3881?

CISA's required action: Apply updates per vendor instructions.

From NVD, CISA KEV, FIRST EPSS and OSV.dev, checked . Status on NVD: Analyzed. The description is NVD's text, quoted as published.

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