Cisco IOS XR Border Gateway Protocol (BGP) Denial-of-Service Vulnerability

Cisco IOS XR 3.4.0 through 3.9.1, when BGP is enabled, does not properly handle unrecognized transitive attributes, which allows remote attackers to cause a denial of service (peering reset) via a crafted prefix announcement, as…

CheckOps priority index

5.0/10 Patch within 7 days

Severity7.5

Probability0.6

Exploitation3/5

Severity = CVSS. Probability = EPSS (FIRST). Exploitation = public signals: KEV, EUVD, ransomware, EPSS above 10 %, no account required.

EPSS · today 5.7% higher than 93.0% of CVEs

CVSS 3.1 7.5 AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:

Exploited for 1,684 days 25 Mar 2022

CISA due date 15 Apr 2022 for US federal agencies

Exploitation probability EPSS · FIRST

EPSS probability (%)Percentile among all CVEs

Exploitation signals 3 / 5

KEV catalog (CISA)25 Mar 2022
Exploited in EUVD (ENISA)25 Mar 2022
Used by ransomwareno
EPSS above 10 %5.7%
No account, over the networkyes

What to do

Fix

Apply the vendor’s fix as soon as it is available.

CISA guidance: Apply updates per vendor instructions.

Meanwhile

Take the service off the internet or restrict access to it, watch the logs and look for signs of compromise.

Manufacturers (CRA)

Exploited vulnerability in your product: early warning to ENISA within 24 h, then notification within 72 h (Article 14 of the Cyber Resilience Act). The CRA explained

Description ENISA EUVD

Affected products

IOS XR

Weaknesses (CWE)

CWE-20

Open source packages OSV

Affected libraries according to OSV, with fixed versions.

Timeline

30 Aug 2010
Published
25 Mar 2022
Exploitation reported (ENISA)
25 Mar 2022
Added to the KEV catalog
15 Apr 2022
CISA remediation due date

References

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