Cisco Issues Warning Over IOS XR Zero-Day Flaw Being Targeted in the Wild

Cisco has warned of an energetic zero-day vulnerability in its router software package which is becoming exploited in the wild and could allow a distant, authenticated attacker to have out memory exhaustion assaults on an affected gadget.

“An attacker could exploit these vulnerabilities by sending crafted IGMP traffic to an impacted product,” Cisco explained in an advisory posted over the weekend.

“A successful exploit could enable the attacker to cause memory exhaustion, ensuing in instability of other procedures. These procedures may include things like, but are not confined to, interior and exterior routing protocols.”


While the firm stated it will release software package fixes to handle the flaw, it did not share a timeline for when it options to make it offered. The networking products maker reported it grew to become aware of makes an attempt to exploit the flaw on August 28.

Tracked as CVE-2020-3566, the severity of the vulnerability has been rated “higher” with a Frequent Vulnerability Scoring Procedure score of 8.6 out of a utmost 10.

The bug influences all Cisco equipment functioning its Internetwork Running Program (IOS) XR Software and stems from an situation in the Length Vector Multicast Routing Protocol (DVMRP) aspect that can make it attainable for an adversary to mail specifically crafted World wide web Group Management Protocol (IGMP) packets to the inclined gadget in dilemma and exhaust approach memory.

IGMP is ordinarily utilised to proficiently use assets for multicasting apps when supporting streaming content these as online online video streaming and gaming. The flaw lies in the manner IOS XR Program queues these packets, perhaps causing memory exhaustion and disruption of other procedures.

Whilst there are no workarounds to solve the difficulty, Cisco endorses administrators to operate the “present igmp interface” command to determine if multicast routing is enabled.

“If the output of ‘show igmp interface’ is vacant, multicast routing is not enabled and the gadget is not impacted by these vulnerabilities,” the company mentioned.

Furthermore, admins can also examine the method logs for signals of memory exhaustion and apply amount-limiting to lower IGMP site visitors costs to mitigate the chance.

Cisco did not elaborate on how the attackers have been exploiting this vulnerability and with what target in brain.

But given that useful resource exhaustion attacks are also a type of denial-of-services attacks, it wouldn’t be stunning if bad actors are leveraging the flaw to interfere with the standard operating of the procedure.

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