CVE-2019-1739
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.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (2.52%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
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 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.
- CVSS 3.1
- 7.5 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- EPSS
- 2.52% probability · 85th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-20
- Affected
- cisco/ios · cisco/ios xe
- Source
- psirt@cisco.com
EPSS 2.5% since 26 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
References
- http://www.securityfocus.com/bid/107597Broken Link, Third Party Advisory, VDB Entry
- https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20190327-nbarPatch, Vendor Advisory
- http://www.securityfocus.com/bid/107597Broken Link, Third Party Advisory, VDB Entry
- https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20190327-nbarPatch, Vendor Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.