CVE-2019-1740: Cisco IOS and IOS XE Software Network-Based Application Recognition Denial of Service Vulnerabilities

Published Mar 27, 2019

Updated

A vulnerability in the Network-Based Application Recognition (NBAR) feature of Cisco IOS Software and Cisco IOS XE Software could allow an unauthenticated, remote attacker to cause an affected device to reload. This vulnerability are due to a parsing issue on DNS packets. An attacker could exploit this vulnerability by sending crafted DNS packets through routers that are running an affected version and have NBAR enabled. A successful exploit could allow the attacker to cause the affected device to reload, resulting in a denial of service (DoS) condition.

Affected Software

149 affected components

Cisco IOS XE=3.2.0ja

Cisco IOS XE=3.16.0as

Cisco IOS XE=3.16.0bs

Cisco IOS XE=3.16.0cs

Cisco IOS XE=3.16.0s

Cisco IOS XE=3.16.1as

Cisco IOS XE=3.16.1s

Cisco IOS XE=3.16.2as

Cisco IOS XE=3.16.2bs

Cisco IOS XE=3.16.2s

Cisco IOS XE=3.16.3as

Cisco IOS XE=3.16.3s

Cisco IOS XE=3.16.4as

Cisco IOS XE=3.16.4bs

Cisco IOS XE=3.16.4cs

Cisco IOS XE=3.16.4ds

Cisco IOS XE=3.16.4es

Cisco IOS XE=3.16.4gs

Cisco IOS XE=3.16.4s

Cisco IOS XE=3.16.5as

Cisco IOS XE=3.16.5s

Cisco IOS XE=3.17.0s

Cisco IOS XE=3.17.1as

Cisco IOS XE=3.17.1s

Cisco IOS XE=3.17.2s

Cisco IOS XE=3.17.3s

Cisco IOS XE=3.17.4s

Cisco IOS XE=3.18.0as

Cisco IOS XE=3.18.0s

Cisco IOS XE=3.18.0sp

Cisco IOS XE=3.18.1asp

Cisco IOS XE=3.18.1bsp

Cisco IOS XE=3.18.1csp

Cisco IOS XE=3.18.1gsp

Cisco IOS XE=3.18.1hsp

Cisco IOS XE=3.18.1isp

Cisco IOS XE=3.18.1s

Cisco IOS XE=3.18.1sp

Cisco IOS XE=3.18.2asp

Cisco IOS XE=3.18.2s

Cisco IOS XE=3.18.2sp

Cisco IOS XE=3.18.3s

Cisco IOS XE=3.18.4s

Cisco IOS XE=16.2.1

Cisco IOS XE=16.2.2

Cisco IOS XE=16.3.1

Cisco IOS XE=16.3.1a

Cisco IOS XE=16.3.2

Cisco IOS XE=16.3.3

Cisco IOS XE=16.3.4

Cisco IOS XE=16.4.1

Cisco IOS XE=16.4.2

Cisco IOS XE=16.4.3

Cisco IOS XE=16.5.1

Cisco IOS XE=16.5.1a

Cisco IOS XE=16.5.1b

Cisco IOS XE=16.9.3s

Cisco IOS XE=16.9.4c

cisco IOS=15.3\(3\)jd

cisco IOS=15.3\(3\)jd2

cisco IOS=15.3\(3\)jd3

cisco IOS=15.3\(3\)jd4

cisco IOS=15.3\(3\)jd5

cisco IOS=15.3\(3\)jd6

cisco IOS=15.3\(3\)jd7

cisco IOS=15.3\(3\)jd8

cisco IOS=15.3\(3\)jd9

cisco IOS=15.3\(3\)jd11

cisco IOS=15.3\(3\)jd12

cisco IOS=15.3\(3\)jd13

cisco IOS=15.3\(3\)jd14

cisco IOS=15.3\(3\)je

cisco IOS=15.3\(3\)jf

cisco IOS=15.3\(3\)jf1

cisco IOS=15.3\(3\)jf2

cisco IOS=15.3\(3\)jf4

cisco IOS=15.3\(3\)jf5

cisco IOS=15.3\(3\)jg

cisco IOS=15.3\(3\)jg1

cisco IOS=15.3\(3\)jh

cisco IOS=15.3\(3\)jk6

cisco IOS=15.3\(3\)jnp

cisco IOS=15.3\(3\)jnp1

cisco IOS=15.3\(3\)jnp3

cisco IOS=15.3\(3\)jpb

cisco IOS=15.3\(3\)jpb1

cisco IOS=15.3\(3\)jpc

cisco IOS=15.3\(3\)jpc1

cisco IOS=15.3\(3\)jpc2

cisco IOS=15.3\(3\)jpc3

cisco IOS=15.3\(3\)jpc5

cisco IOS=15.3\(3\)jpd

cisco IOS=15.5\(3\)m

cisco IOS=15.5\(3\)m0a

cisco IOS=15.5\(3\)m1

cisco IOS=15.5\(3\)m2

cisco IOS=15.5\(3\)m2a

cisco IOS=15.5\(3\)m3

cisco IOS=15.5\(3\)m4

cisco IOS=15.5\(3\)m4a

cisco IOS=15.5\(3\)m4b

cisco IOS=15.5\(3\)m4c

cisco IOS=15.5\(3\)m5

cisco IOS=15.5\(3\)s

cisco IOS=15.5\(3\)s0a

cisco IOS=15.5\(3\)s1

cisco IOS=15.5\(3\)s1a

cisco IOS=15.5\(3\)s2

cisco IOS=15.5\(3\)s3

cisco IOS=15.5\(3\)s4

cisco IOS=15.5\(3\)s5

cisco IOS=15.5\(3\)sn

cisco IOS=15.5\(3\)sn0a

cisco IOS=15.6\(1\)s

cisco IOS=15.6\(1\)s1

cisco IOS=15.6\(1\)s2

cisco IOS=15.6\(1\)s3

cisco IOS=15.6\(1\)s4

cisco IOS=15.6\(1\)sn

cisco IOS=15.6\(1\)sn1

cisco IOS=15.6\(1\)sn2

cisco IOS=15.6\(1\)sn3

cisco IOS=15.6\(1\)t

cisco IOS=15.6\(1\)t0a

cisco IOS=15.6\(1\)t1

cisco IOS=15.6\(1\)t2

cisco IOS=15.6\(2\)s

cisco IOS=15.6\(2\)s1

cisco IOS=15.6\(2\)s2

cisco IOS=15.6\(2\)s3

cisco IOS=15.6\(2\)s4

cisco IOS=15.6\(2\)sn

cisco IOS=15.6\(2\)t

cisco IOS=15.6\(2\)t0a

cisco IOS=15.6\(2\)t1

cisco IOS=15.6\(2\)t2

cisco IOS=15.6\(3\)m

cisco IOS=15.6\(3\)m0a

cisco IOS=15.6\(3\)m1

cisco IOS=15.6\(3\)m1a

cisco IOS=15.6\(3\)m1b

cisco IOS=15.6\(3\)sn

cisco IOS=15.6\(4\)sn

cisco IOS=15.6\(5\)sn

cisco IOS=15.6\(6\)sn

cisco IOS=15.6\(7\)sn

cisco IOS=15.6\(7\)sn1

cisco IOS=15.6\(7\)sn2

cisco IOS=15.6\(7\)sn3

Remediation

Patch Available

https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20190327-nbar

Event History

Mar 27, 2019

CVE Published

via MITRE·11:25 PM

Data Sourced

via MITRE·11:25 PM

DescriptionSeverityWeakness

Mar 28, 2019

Data Sourced

via NVD·12:29 AM

RemedyDescriptionSeverityWeaknessAffected Software

Frequently Asked Questions

What is the severity of CVE-2019-1740?

CVE-2019-1740 is classified as a high severity vulnerability due to its potential to cause a device to reload unexpectedly.

How do I fix CVE-2019-1740?

To fix CVE-2019-1740, users should upgrade to the fixed version of the affected Cisco IOS Software or Cisco IOS XE Software as recommended in the security advisory.

Who is affected by CVE-2019-1740?

CVE-2019-1740 affects devices running vulnerable versions of Cisco IOS Software and Cisco IOS XE Software that utilize the Network-Based Application Recognition (NBAR) feature.

What type of vulnerability is CVE-2019-1740?

CVE-2019-1740 is a remote denial of service vulnerability caused by improper parsing of DNS packets.

Can CVE-2019-1740 be exploited remotely?

Yes, CVE-2019-1740 can be exploited by unauthenticated attackers remotely, leading to a device reload.