How severe is CVE-2018-0476?

CVE-2018-0476 has a CVSS 3.x base score of 5.9, rated medium severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2018-0476 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 14% (96th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2018-0476?

CVE-2018-0476 primarily affects Cisco Ios Xe. In total, 3 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2018-0476?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2018-0476 published?

CVE-2018-0476 was published on 2018-10-05 and last updated on 2026-06-17.

CVE-2018-0476

CVE-2018-0476 is a medium-severity vulnerability in Cisco Ios Xe with a CVSS 3.x base score of 5.9. Its EPSS exploit-prediction score of 14% places it in the 96th percentile, indicating an elevated likelihood of exploitation. The underlying weakness is classified as CWE-399.

Key facts

Severity: Medium (CVSS 3.x base score 5.9)
CVSS v2: 7.1
EPSS exploit prediction: 14% (96th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-399
Affected product: Cisco Ios Xe
Published: 2018-10-05
Last modified: 2026-06-17

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.

Frequently asked questions

What is 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. 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.
How severe is CVE-2018-0476?: CVE-2018-0476 has a CVSS 3.x base score of 5.9, rated medium severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2018-0476 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 14% (96th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2018-0476?: CVE-2018-0476 primarily affects Cisco Ios Xe. In total, 3 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2018-0476?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2018-0476 published?: CVE-2018-0476 was published on 2018-10-05 and last updated on 2026-06-17.

References

Affected products (3)

cpe:2.3:o:cisco:ios_xe:15.5\(3\)s5.1:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xe:15.5\(3\)s6.1:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xe:16.6.2:*:*:*:*:*:*:*

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