CVE-2025-20316
MediumCVSS 5.3Exploitation Probability (EPSS)
Low risk24th percentile - higher than 24% of all known CVEs
Summary
A vulnerability in the access control list (ACL) programming of Cisco IOS XE Software for Cisco Catalyst 9500X and 9600X Series Switches could allow an unauthenticated, remote attacker to bypass a configured ACL on an affected device. This vulnerability is due to the flooding of traffic from an unlearned MAC address on a switch virtual interface (SVI) that has an egress ACL applied. An attacker could exploit this vulnerability by causing the VLAN to flush its MAC address table. This condition can also occur if the MAC address table is full. A successful exploit could allow the attacker to bypass an egress ACL on an affected device.
Risk Assessment
Bypassing an egress ACL may allow an attacker to circumvent access controls and reach protected network segments. This may lead to unauthorized traffic and violation of security policies.
Recommendation
Apply Cisco IOS XE fixes on affected Catalyst 9500X/9600X switches and consider additional access control measures and MAC table monitoring.
Other vulnerabilities in Cisco IOS XE
See all- CVE-2017-12230High
A vulnerability in the web-based user interface of Cisco IOS XE 16.2 could allow an authenticated, remote attacker to elevate their privileges on an affected device. The vulnerability is due to incorrect default permission settings for new users created using the web UI.
- CVE-2016-6378High
Cisco IOS XE versions 3.1 through 3.17 and 16.1 through 16.2 are vulnerable to an attack that can cause device reload via crafted ICMP packets requiring NAT.
- CVE-2016-6386High
Cisco IOS XE versions 3.1 through 3.17 and 16.1 on 64-bit platforms allow remote attackers to cause a denial of service (data-structure corruption and device reload) via fragmented IPv4 packets.
- CVE-2015-6282High
Cisco IOS XE 2.x and 3.x before 3.10.6S, 3.11.xS through 3.13.xS before 3.13.3S, and 3.14.xS through 3.15.xS before 3.15.1S are vulnerable to an attack that can lead to denial of service by causing device reload. Attackers can exploit IPv4 packets that require NAT and MPLS actions.
- CVE-2015-0645High
The Layer 4 Redirect (L4R) feature in Cisco IOS XE 2.x and 3.x before 3.10.4S, 3.11 before 3.11.3S, 3.12 before 3.12.2S, 3.13 before 3.13.1S, 3.14 before 3.14.0S, and 3.15 before 3.15.0S allows remote attackers to cause a denial of service (device reload) via malformed IPv4 or IPv6 packets.
- CVE-2015-0644High
AppNav in Cisco IOS XE versions 3.8 through 3.10 before 3.10.3S, 3.11 before 3.11.3S, 3.12 before 3.12.1S, 3.13 before 3.13.0S, 3.14 before 3.14.0S, and 3.15 before 3.15.0S allows remote attackers to execute arbitrary code or cause a denial of service (device reload) via a crafted TCP packet, aka Bug ID CSCuo53622.
- CVE-2015-0641High
Cisco IOS XE versions 2.x and 3.x before 3.9.0S, 3.10 before 3.10.0S, 3.11 before 3.11.0S, 3.12 before 3.12.0S, 3.13 before 3.13.0S, 3.14 before 3.14.0S, and 3.15 before 3.15.0S are vulnerable to a denial of service attack that can cause device reload via crafted IPv6 packets. This vulnerability is known as Bug ID CSCub68073.
- CVE-2015-0639High
The Common Flow Table (CFT) feature in Cisco IOS XE versions 3.6 and 3.7 before 3.7.1S and in versions 3.8 to 3.15 before respective updates allows remote attackers to cause a denial of service (device reload) via malformed IPv6 packets with IPv4 UDP encapsulation.
- CVE-2017-6663MediumActively exploited
A vulnerability in the Autonomic Networking feature of Cisco IOS Software and Cisco IOS XE Software allows an unauthenticated, adjacent attacker to cause autonomic nodes to reload, resulting in a denial of service (DoS). Known affected releases include Denali-16.2.1 and Denali-16.3.1.
- CVE-2025-20338Medium
A vulnerability in the CLI of Cisco IOS XE Software could allow an authenticated, local attacker with administrative privileges to execute arbitrary commands as root on the underlying operating system of an affected device. This is due to insufficient validation of user arguments passed to specific CLI commands. An attacker could log in with level 15 credentials and use crafted commands.
Original NVD description (English source)
A vulnerability in the access control list (ACL) programming of Cisco IOS XE Software for Cisco Catalyst 9500X and 9600X Series Switches could allow an unauthenticated, remote attacker to bypass a configured ACL on an affected device. This vulnerability is due to the flooding of traffic from an unlearned MAC address on a switch virtual interface (SVI) that has an egress ACL applied. An attacker could exploit this vulnerability by causing the VLAN to flush its MAC address table. This condition can also occur if the MAC address table is full. A successful exploit could allow the attacker to bypass an egress ACL on an affected device.
Vulnerability data from NVD (NIST) · CISA KEV · EPSS