CVE-2019-1738: Cisco IOS and IOS XE Software Network-Based Application Recognition Denial of Service Vulnerability

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 is due to a parsing issue on DNS packets. An attacker could exploit these vulnerabilities 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

165 affected components

cisco IOS=15.1\(2\)sg8a

cisco IOS=15.1\(3\)svg3d

cisco IOS=15.1\(3\)svi1b

cisco IOS=15.1\(3\)svk4b

cisco IOS=15.1\(3\)svk4c

cisco IOS=15.1\(3\)svm3

cisco IOS=15.1\(3\)svn2

cisco IOS=15.1\(3\)svo1

cisco IOS=15.1\(3\)svo2

cisco IOS=15.1\(3\)svo3

cisco IOS=15.1\(3\)svo4

cisco IOS=15.1\(3\)svp1

cisco IOS=15.1\(3\)svp2

cisco IOS=15.1\(4\)m12c

cisco IOS=15.2\(3\)ea1

cisco IOS=15.2\(4a\)ea5

cisco IOS=15.3\(3\)ja1n

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\(3\)jf35

cisco IOS=15.3\(3\)jg

cisco IOS=15.3\(3\)jg1

cisco IOS=15.3\(3\)jh

cisco IOS=15.3\(3\)ji

cisco IOS=15.3\(3\)ji2

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\(3\)m5a

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\(2\)sp3b

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 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=3.17.3s

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

Remediation

Patch Available

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

Event History

Mar 27, 2019

CVE Published

via MITRE·11:15 PM

Data Sourced

via MITRE·11:15 PM

DescriptionSeverityWeakness

Mar 28, 2019

Data Sourced

via NVD·12:29 AM

RemedyDescriptionSeverityWeaknessAffected Software

Frequently Asked Questions

What is the severity of CVE-2019-1738?

CVE-2019-1738 has a high severity rating, allowing attackers to cause impacted devices to reload without authentication.

How do I fix CVE-2019-1738?

To fix CVE-2019-1738, upgrade your Cisco IOS Software to a version that addresses this vulnerability as outlined in Cisco's advisory.

What products are affected by CVE-2019-1738?

CVE-2019-1738 affects various versions of Cisco IOS and IOS XE software, specifically some versions in 15.1, 15.2, 15.3, 15.5, and 15.6.

Can CVE-2019-1738 be exploited remotely?

Yes, CVE-2019-1738 can be exploited remotely by unauthenticated attackers through crafted DNS packets.

What measures should I take regarding CVE-2019-1738?

Users should apply the recommended patches or update to secure software versions to mitigate the risks associated with CVE-2019-1738.