CVE-2018-0476
A vulnerability in the Network Address Translation (NAT) Session Initiation Protocol (SIP) Application Layer Gateway (ALG) of Cisco IOS XE Software could allow an unauthenticated, remote attacker to cause an affected device to reload.
Does this matter?
EPSS puts the probability of exploitation in the next 30 days at 13.7%, higher than 96% of all known CVEs. Patch or mitigate before the next change window.
Description
A vulnerability in the Network Address Translation (NAT) Session Initiation Protocol (SIP) Application Layer Gateway (ALG) of Cisco IOS XE Software could allow an unauthenticated, remote attacker to cause an affected device to reload. The vulnerability is due to improper processing of SIP packets in transit while NAT is performed on an affected device. An unauthenticated, remote attacker could exploit this vulnerability by sending crafted SIP packets via UDP port 5060 through an affected device that is performing NAT for SIP packets. A successful exploit could allow an attacker to cause the device to reload, resulting in a denial of service (DoS) condition.
- CVSS 3.0
- 5.9 MEDIUMCVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
- EPSS
- 13.70% probability · 96th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-399
- Affected
- cisco/ios xe
- Source
- psirt@cisco.com
EPSS moved from 10.2% on 21 September 2026 to 13.7% on 27 October 2026. The dashed line is the ten per cent mark our analysts treat as “patch before the next change window”.
References
- http://www.securityfocus.com/bid/105419Third Party Advisory, VDB Entry
- http://www.securitytracker.com/id/1041734Third Party Advisory, VDB Entry
- http://www.securitytracker.com/id/1041737Third Party Advisory, VDB Entry
- https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20180926-sip-algVendor Advisory
- http://www.securityfocus.com/bid/105419Third Party Advisory, VDB Entry
- http://www.securitytracker.com/id/1041734Third Party Advisory, VDB Entry
- http://www.securitytracker.com/id/1041737Third Party Advisory, VDB Entry
- https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20180926-sip-algVendor Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.