Cisco Finally Patches 0-Day Exploit Disclosed In Wikileaks
Vulnerabilities mentionedAll →
| CVE | Vulnerability | CVSS | EPSS | Flags | Affected | Exposure | Published |
|---|---|---|---|---|---|---|---|
| CVE-2017-3881 | Unauthenticated RCE in Cisco IOS/IOS XE switches via malformed CMP Telnet options CVE-2017-3881 is a critical (CVSS 9.8) unauthenticated remote code execution flaw, classified CWE-20, in the Cluster Management Protocol (CMP) processing code of Cisco IOS and IOS XE, which uses Telnet internally for signaling between switch cluster members. Because affected devices accept CMP-specific Telnet options on any inbound Telnet connection and mishandle malformed ones, an unauthenticated attacker who opens a Telnet session to a Telnet-enabled device and sends malformed CMP options can trigger the flaw. Successful exploitation lets the attacker execute arbitrary code with elevated privileges, gaining full control of the device, or force a reload of the switch. Affected hardware spans over 300 switching models per related coverage — Catalyst switches, Embedded Service 2020 and IE Industrial Ethernet switches, several EtherSwitch service modules, the ME 4924-10GE, RF Gateway 10, and the CGESM module for HP — running IOS or IOS XE with Telnet enabled; devices that accept only SSH are not remotely exploitable. The bug was disclosed via the March 2017 WikiLeaks Vault 7 CIA leak (tied to the 'Zero Disco' toolkit in related coverage), patched by Cisco that month, has a public PoC (Exploit-DB 41872), was added to CISA's KEV on 2022-03-25 (ransomware use unknown), and EPSS rates a 99% probability of exploitation in 30 days (100th percentile), so in-the-wild exploitation should be assumed. Do: Upgrade affected switches to the fixed IOS/IOS XE releases listed in Cisco's advisory for bug CSCvd48893 (the CISA KEV required action is to apply the vendor updates). Until patched, disable Telnet on vty lines and use SSH, or restrict inbound TCP/23 to trusted management hosts, since the bug is only reachable via inbound Telnet sessions. Audit configurations for 'transport input telnet' and prioritize internet-facing or widely reachable Catalyst, IE industrial, and EtherSwitch-service-module devices. | 9.8 | 99% | KEV PoC |
| mass≈1M+ deployed affected switches across 300+ models (only the Telnet-enabled subset is exploitable, likely hundreds of thousands of exposed systems) |
Full article395 words · extracted from thehackernews.com · click to collapse
The Hacker NewsMay 10, 2017
Cisco Systems has finally released an update for its IOS and IOS XE software to address a critical vulnerability, disclosed nearly two months back in the CIA Vault 7 leak, that affects more than 300 of its switch models.
The company identified the vulnerability in its product while analyzing "Vault 7" dump — thousands of documents and files leaked by Wikileaks, claiming to detail hacking tools and tactics of the U.S. Central Intelligence Agency (CIA).
As previously reported, the vulnerability (CVE-2017-3881) resides in the Cluster Management Protocol (CMP) — which uses Telnet or SSH to deliver signals and commands on internal networks — in Cisco IOS and Cisco IOS XE Software.
The vulnerability can be exploited remotely by sending "malformed CMP-specific Telnet options while establishing a Telnet session with an affected Cisco device configured to accept Telnet connections," researchers say.
The company warned users on April 10 that an exploit targeting the flaw had been made public (here's a proof-of-concept (PoC) exploit) and provided some mitigation advice, but patched the issue this week only.
Once exploited, an unauthenticated, remote attacker can remotely execute malicious code on a device with elevated privileges to take full control of the device or cause a reboot of the affected device.
The vulnerability is in the default configuration of the affected Cisco devices and affects 264 Catalyst switches, 51 industrial Ethernet switches, and 3 other devices if they are running IOS and are configured to accept Telnet connections.
The affected Cisco switch models include Catalyst switches, Embedded Service 2020 switches, IE Industrial Ethernet switches, ME 4924-10GE switch, Enhanced Layer 2/3 EtherSwitch Service Module, Enhanced Layer 2 EtherSwitch Service Module, RF Gateway 10, SM-X Layer 2/3 EtherSwitch Service Module, and Gigabit Ethernet Switch Module for HP (check the list of affected models here).
The vulnerability was given a score of 9.8 (higher level of risk) based on the Common Vulnerability Scoring System, which means the issue is truly bad.
The only mitigation available for users was to disable the Telnet connection to the switch devices in favor of SSH, but now since the company has patched the issue, administrators are strongly advised to install the patch as soon as possible.
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Text extracted automatically; images, tables and formatting may be missing. Original: https://thehackernews.com/2017/05/cisco-network-switch-update.html