Connect with us

Hi, what are you looking for?


Network Security

Cisco Says Hackers Targeting Zero-Days in Carrier-Grade Routers

Cisco has warned that hackers are targeting not one, but two unpatched vulnerabilities in the DVMRP feature of IOS XR software that runs on many carrier-grade routers. 

Cisco has warned that hackers are targeting not one, but two unpatched vulnerabilities in the DVMRP feature of IOS XR software that runs on many carrier-grade routers. 

Over the weekend, the company published an advisory to warn of active attacks targeting a security flaw (CVE-2020-3566) in the Distance Vector Multicast Routing Protocol (DVMRP) feature of IOS XR to cause memory exhaustion denial of service (DoS). 

On Monday, the tech giant has updated the advisory to add another CVE to it, namely CVE-2020-3569, which impacts the very same feature and has similar consequences. 

Both issues, the company reveals, can be exploited remotely, by an unauthenticated attacker, by sending crafted IGMP traffic to a vulnerable device. 

The bugs exist because there is insufficient queue management for Internet Group Management Protocol (IGMP) packets.

According to the company, all Cisco devices that are running any release of IOS XR software are affected, provided that an active interface is configured under multicast routing. Impacted devices include: ASR 9000, NCS 5500, 8000, as well as NCS 540 & 560 series routers.

Cisco has shared information on mitigation steps organizations can take to limit exposure, but has yet to release software updates to address these vulnerabilities. 

No workarounds to address the two issues have been detailed yet, but Cisco has published indicators of compromise to help administrators determine whether attackers are exploiting the vulnerabilities in their devices.

Advertisement. Scroll to continue reading.

Related: Attackers Actively Targeting Cisco IOS XR Vulnerability

Related: Cisco Patches High-Severity Vulnerabilities in NX-OS Software

Related: Default Credentials Expose Cisco ENCS, CSP Appliances to Attacks

Written By

Ionut Arghire is an international correspondent for SecurityWeek.

Click to comment

Daily Briefing Newsletter

Subscribe to the SecurityWeek Email Briefing to stay informed on the latest threats, trends, and technology, along with insightful columns from industry experts.

Join us as we delve into the transformative potential of AI, predictive ChatGPT-like tools and automation to detect and defend against cyberattacks.


As cybersecurity breaches and incidents escalate, the cyber insurance ecosystem is undergoing rapid and transformational change.


Expert Insights

Related Content

Identity & Access

Zero trust is not a replacement for identity and access management (IAM), but is the extension of IAM principles from people to everyone and...


Less than a week after announcing that it would suspended service indefinitely due to a conflict with an (at the time) unnamed security researcher...

Data Breaches

OpenAI has confirmed a ChatGPT data breach on the same day a security firm reported seeing the use of a component affected by an...

Risk Management

The supply chain threat is directly linked to attack surface management, but the supply chain must be known and understood before it can be...

IoT Security

A group of seven security researchers have discovered numerous vulnerabilities in vehicles from 16 car makers, including bugs that allowed them to control car...


A researcher at IOActive discovered that home security systems from SimpliSafe are plagued by a vulnerability that allows tech savvy burglars to remotely disable...


Patch Tuesday: Microsoft warns vulnerability (CVE-2023-23397) could lead to exploitation before an email is viewed in the Preview Pane.


Patch Tuesday: Microsoft calls attention to a series of zero-day remote code execution attacks hitting its Office productivity suite.