• Home
  • Cyber Crime
  • Cyber warfare
  • APT
  • Data Breach
  • Deep Web
  • Digital ID
  • Hacking
  • Hacktivism
  • Intelligence
  • Internet of Things
  • Laws and regulations
  • Malware
  • Mobile
  • Reports
  • Security
  • Social Networks
  • Terrorism
  • ICS-SCADA
  • POLICIES
  • Contact me
MUST READ

Security Affairs newsletter Round 531 by Pierluigi Paganini – INTERNATIONAL EDITION

 | 

North Korea-linked threat actors spread macOS NimDoor malware via fake Zoom updates

 | 

Critical Sudo bugs expose major Linux distros to local Root exploits

 | 

Google fined $314M for misusing idle Android users' data

 | 

A flaw in Catwatchful spyware exposed logins of +62,000 users

 | 

China-linked group Houken hit French organizations using zero-days

 | 

Cybercriminals Target Brazil: 248,725 Exposed in CIEE One Data Breach

 | 

Europol shuts down Archetyp Market, longest-running dark web drug marketplace

 | 

Kelly Benefits data breach has impacted 550,000 people, and the situation continues to worsen as the investigation progresses

 | 

Cisco removed the backdoor account from its Unified Communications Manager

 | 

U.S. Sanctions Russia's Aeza Group for aiding crooks with bulletproof hosting

 | 

Qantas confirms customer data breach amid Scattered Spider attacks

 | 

CVE-2025-6554 is the fourth Chrome zero-day patched by Google in 2025

 | 

U.S. CISA adds TeleMessage TM SGNL flaws to its Known Exploited Vulnerabilities catalog

 | 

A sophisticated cyberattack hit the International Criminal Court

 | 

Esse Health data breach impacted 263,000 individuals

 | 

Europol dismantles €460M crypto scam targeting 5,000 victims worldwide

 | 

CISA and U.S. Agencies warn of ongoing Iranian cyber threats to critical infrastructure

 | 

U.S. CISA adds Citrix NetScaler flaw to its Known Exploited Vulnerabilities catalog

 | 

Canada bans Hikvision over national security concerns

 | 
  • Home
  • Cyber Crime
  • Cyber warfare
  • APT
  • Data Breach
  • Deep Web
  • Digital ID
  • Hacking
  • Hacktivism
  • Intelligence
  • Internet of Things
  • Laws and regulations
  • Malware
  • Mobile
  • Reports
  • Security
  • Social Networks
  • Terrorism
  • ICS-SCADA
  • POLICIES
  • Contact me
  • Home
  • Breaking News
  • Security
  • Hackers are trying to exploit DoS flaw in Cisco IOS XR software running in carrier-grade routers

Hackers are trying to exploit DoS flaw in Cisco IOS XR software running in carrier-grade routers

Pierluigi Paganini August 31, 2020

Cisco warns that threat actors are attempting to exploit a high severity DoS flaw in its Cisco IOS XR software that runs on carrier-grade routers.

Cisco warned over the weekend that attackers are trying to exploit a high severity memory exhaustion denial-of-service (DoS) vulnerability (CVE-2020-3566) affecting the Cisco IOS XR Network OS that runs on carrier-grade routers.

Cisco IOS XR Network OS currently run on multiple router families, including NCS 540 & 560, NCS 5500, 8000, and ASR 9000 series routers.

This flaw affects any Cisco device that is running any release of Cisco IOS XR Software if an active interface is configured under multicast routing.

The bad news is that the vulnerability has yet to be addressed by Cisco, at the time of writing the company issued a security advisory that includes mitigation.

“A vulnerability in the Distance Vector Multicast Routing Protocol (DVMRP) feature of Cisco IOS XR Software could allow an unauthenticated, remote attacker to exhaust process memory of an affected device.” reads the advisory.

“On August 28, 2020, the Cisco Product Security Incident Response Team (PSIRT) became aware of attempted exploitation of this vulnerability in the wild.” 

The vulnerability is caused by insufficient queue management for Internet Group Management Protocol (IGMP) packets, it could be exploited by an attacker by sending crafted IGMP traffic to a vulnerable device.

A successful attack could cause memory exhaustion, resulting in instability of other processes, including interior and exterior routing protocols.

The advisory recommends users to run the show igmp interface command to determine if multicast routing is enabled on their device.

Running the command on IOS XR routers were multicast routing is not enabled will produce an empty output.

 The following output shows a device with multicast routing enabled:

RP/0/0/CPU0:router# show igmp interface

Loopback0 is up, line protocol is up
  Internet address is 10.144.144.144/32
  IGMP is enabled on interface
  Current IGMP version is 3
  IGMP query interval is 60 seconds
  IGMP querier timeout is 125 seconds
  IGMP max query response time is 10 seconds
  Last member query response interval is 1 seconds
  IGMP activity: 3 joins, 0 leaves
  IGMP querying router is 10.144.144.144 (this system)
TenGigE0/4/0/0 is up, line protocol is up
  Internet address is 10.114.8.44/24
  IGMP is enabled on interface
  Current IGMP version is 3
  IGMP query interval is 60 seconds
  IGMP querier timeout is 125 seconds
  IGMP max query response time is 10 seconds
  Last member query response interval is 1 seconds
  IGMP activity: 9 joins, 4 leaves
  IGMP querying router is 10.114.8.11

The advisory states that there are multiple mitigations available to customers depending on their needs, for example, implementing a rate limiter to reduce the traffic rate and increase the time necessary for successful exploitation.

“This will require that customers understand their current rate of IGMP traffic and set a rate lower than the current average rate.” continues the advisory. “In configuration mode, the customer can enter the lpts pifib hardware police flow igmp rate command as follows:

RP/0/0/CPU0:router(config)# lpts pifib hardware police flow igmp rate <value> 

This command will not remove the exploit vector.”

Users can also implement an access control entry (ACE) to an existing interface access control list (ACL) or a new ACL to deny inbound DVRMP traffic to interfaces with multicast routing enabled.

Cisco also recommends disabling IGMP routing for an interface where processing IGMP traffic is not necessary by entering IGMP router configuration mode.

[adrotate banner=”9″][adrotate banner=”12″]

Pierluigi Paganini

(SecurityAffairs – hacking, Cisco IOS XR)

[adrotate banner=”5″]

[adrotate banner=”13″]


facebook linkedin twitter

CISCO Cisco IOS XR DOS Hacking hacking news

you might also like

Pierluigi Paganini July 06, 2025
Security Affairs newsletter Round 531 by Pierluigi Paganini – INTERNATIONAL EDITION
Read more
Pierluigi Paganini July 05, 2025
North Korea-linked threat actors spread macOS NimDoor malware via fake Zoom updates
Read more

leave a comment

newsletter

Subscribe to my email list and stay
up-to-date!

    recent articles

    Security Affairs newsletter Round 531 by Pierluigi Paganini – INTERNATIONAL EDITION

    Breaking News / July 06, 2025

    North Korea-linked threat actors spread macOS NimDoor malware via fake Zoom updates

    Malware / July 05, 2025

    Critical Sudo bugs expose major Linux distros to local Root exploits

    Security / July 04, 2025

    Google fined $314M for misusing idle Android users' data

    Laws and regulations / July 04, 2025

    A flaw in Catwatchful spyware exposed logins of +62,000 users

    Malware / July 04, 2025

    To contact me write an email to:

    Pierluigi Paganini :
    pierluigi.paganini@securityaffairs.co

    LEARN MORE

    QUICK LINKS

    • Home
    • Cyber Crime
    • Cyber warfare
    • APT
    • Data Breach
    • Deep Web
    • Digital ID
    • Hacking
    • Hacktivism
    • Intelligence
    • Internet of Things
    • Laws and regulations
    • Malware
    • Mobile
    • Reports
    • Security
    • Social Networks
    • Terrorism
    • ICS-SCADA
    • POLICIES
    • Contact me

    Copyright@securityaffairs 2024

    We use cookies on our website to give you the most relevant experience by remembering your preferences and repeat visits. By clicking “Accept All”, you consent to the use of ALL the cookies. However, you may visit "Cookie Settings" to provide a controlled consent.
    Cookie SettingsAccept All
    Manage consent

    Privacy Overview

    This website uses cookies to improve your experience while you navigate through the website. Out of these cookies, the cookies that are categorized as necessary are stored on your browser as they are essential for the working of basic functionalities...
    Necessary
    Always Enabled
    Necessary cookies are absolutely essential for the website to function properly. This category only includes cookies that ensures basic functionalities and security features of the website. These cookies do not store any personal information.
    Non-necessary
    Any cookies that may not be particularly necessary for the website to function and is used specifically to collect user personal data via analytics, ads, other embedded contents are termed as non-necessary cookies. It is mandatory to procure user consent prior to running these cookies on your website.
    SAVE & ACCEPT