Security

Cisco fixed multiple severe vulnerabilities in its IOS and IOS XE software

Cisco addressed tens of vulnerabilities in its IOS and IOS XE software, six of these issues have been rated ‘high severity’.

Cisco published the March 2023 Semiannual IOS and IOS XE Software Security Advisory that addresses several vulnerabilities in IOS and IOS XE software.

Below is the list of flaws addressed by the IT giant in this bundled publication:

Cisco Security AdvisoryCVE IDSecurity Impact RatingCVSS Base Score
Cisco IOS and IOS XE Software IPv6 DHCP (DHCPv6) Relay and Server Denial of Service VulnerabilityCVE-2023-20080High8.6
Cisco IOS XE Software Fragmented Tunnel Protocol Packet Denial of Service VulnerabilityCVE-2023-20072High8.6
Cisco IOS XE Software Virtual Fragmentation Reassembly Denial of Service VulnerabilityCVE-2023-20027High8.6
Cisco IOS XE SD-WAN Software Command Injection VulnerabilityCVE-2023-20035High7.8
Cisco IOS XE Software IOx Application Hosting Environment Privilege Escalation VulnerabilityCVE-2023-20065High7.8
Cisco IOS XE Software for Wireless LAN Controllers HTTP Client Profiling Denial of Service VulnerabilityCVE-2023-20067High7.4
Cisco Adaptive Security Appliance Software, Firepower Threat Defense Software, IOS Software, and IOS XE Software IPv6 DHCP (DHCPv6) Client Denial of Service VulnerabilityCVE-2023-20081Medium6.8
Cisco IOS XE Software for Wireless LAN Controllers CAPWAP Join Denial of Service VulnerabilityCVE-2023-20100Medium6.8
Cisco IOS XE Software Web UI Path Traversal VulnerabilityCVE-2023-20066Medium6.5
Cisco IOS XE Software Privilege Escalation VulnerabilityCVE-2023-20029Medium4.4

The most important severe vulnerabilities addressed by the company are:

CVE-2023-20080 (CVSS score 8.6) – Cisco IOS and IOS XE Software IPv6 DHCP (DHCPv6) Relay and Server Denial of Service Vulnerability. An unauthenticated, remote attacker can trigger the flaw to cause DoS condition.

“This vulnerability is due to insufficient validation of data boundaries. An attacker could exploit this vulnerability by sending crafted DHCPv6 messages to an affected device. A successful exploit could allow the attacker to cause the device to reload unexpectedly.” reads the advisory.

CVE-2023-20072 (CVSS score 8.6) – Cisco IOS XE Software Fragmented Tunnel Protocol Packet Denial of Service Vulnerability. An unauthenticated, remote attacker can trigger the flaw to cause an affected system to reload, resulting in a denial of service (DoS) condition.

“This vulnerability is due to the improper handling of large fragmented tunnel protocol packets. One example of a tunnel protocol is Generic Routing Encapsulation (GRE). An attacker could exploit this vulnerability by sending crafted fragmented packets to an affected system.” reads the advisory. “A successful exploit could allow the attacker to cause the affected system to reload, resulting in a DoS condition.”

CVE-2023-20027 (CVSS score 8.6) – Cisco IOS XE Software Virtual Fragmentation Reassembly Denial of Service Vulnerability. An unauthenticated, remote attacker can exploit this vulnerability to cause a denial of service (DoS) condition on a vulnerable device.

“This vulnerability is due to improper reassembly of large packets that occurs when VFR is enabled on either a tunnel interface or on a physical interface that is configured with a maximum transmission unit (MTU) greater than 4,615 bytes. An attacker could exploit this vulnerability by sending fragmented packets through a VFR-enabled interface on an affected device.” reads the advisory. “A successful exploit could allow the attacker to cause the device to reload, resulting in a DoS condition.”

Cisco also addressed an IOS XE SD-WAN software command injection vulnerability tracked as CVE-2023-20035 (CVSS Score 7.8) and an IOS XE Software IOx Application Hosting Environment privilege escalation vulnerability tracked as CVE-2023-20065 (CVSS Score 7.8).

The good news is that the company is not aware of attacks in the wild exploiting one of the flaws addressed with the release of semiannual IOS and IOS XE software security advisory bundle.

Follow me on Twitter: @securityaffairs and Facebook and Mastodon

Pierluigi Paganini

(SecurityAffairs – hacking, IOS XE)

Pierluigi Paganini

Pierluigi Paganini is member of the ENISA (European Union Agency for Network and Information Security) Threat Landscape Stakeholder Group and Cyber G7 Group, he is also a Security Evangelist, Security Analyst and Freelance Writer. Editor-in-Chief at "Cyber Defense Magazine", Pierluigi is a cyber security expert with over 20 years experience in the field, he is Certified Ethical Hacker at EC Council in London. The passion for writing and a strong belief that security is founded on sharing and awareness led Pierluigi to find the security blog "Security Affairs" recently named a Top National Security Resource for US. Pierluigi is a member of the "The Hacker News" team and he is a writer for some major publications in the field such as Cyber War Zone, ICTTF, Infosec Island, Infosec Institute, The Hacker News Magazine and for many other Security magazines. Author of the Books "The Deep Dark Web" and “Digital Virtual Currency and Bitcoin”.

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