Cisco IOS XR up to 24.2.20 Border Gateway Protocol buffer overflow

Summaryinfo

A vulnerability was found in Cisco IOS XR. It has been classified as critical. This vulnerability affects unknown code of the component Border Gateway Protocol. Performing a manipulation results in buffer overflow. This vulnerability is reported as CVE-2025-20115. The attack is possible to be carried out remotely. No exploit exists. Upgrading the affected component is recommended.

Detailsinfo

A vulnerability, which was classified as critical, was found in Cisco IOS XR. This affects an unknown code block of the component Border Gateway Protocol. The manipulation with an unknown input leads to a buffer overflow vulnerability. CWE is classifying the issue as CWE-120. The product copies an input buffer to an output buffer without verifying that the size of the input buffer is less than the size of the output buffer, leading to a buffer overflow. This is going to have an impact on availability. The summary by CVE is:

A vulnerability in confederation implementation for the Border Gateway Protocol (BGP) in Cisco IOS XR Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition. This vulnerability is due to a memory corruption that occurs when a BGP update is created with an AS_CONFED_SEQUENCE attribute that has 255 autonomous system numbers (AS numbers). An attacker could exploit this vulnerability by sending a crafted BGP update message, or the network could be designed in such a manner that the AS_CONFED_SEQUENCE attribute grows to 255 AS numbers or more. A successful exploit could allow the attacker to cause memory corruption, which may cause the BGP process to restart, resulting in a DoS condition. To exploit this vulnerability, an attacker must control a BGP confederation speaker within the same autonomous system as the victim, or the network must be designed in such a manner that the AS_CONFED_SEQUENCE attribute grows to 255 AS numbers or more.

The advisory is shared at sec.cloudapps.cisco.com. This vulnerability is uniquely identified as CVE-2025-20115 since 10/10/2024. The exploitability is told to be easy. It is possible to initiate the attack remotely. No form of authentication is needed for exploitation. Neither technical details nor an exploit are publicly available. The price for an exploit might be around USD $5k-$25k at the moment (estimation calculated on 08/01/2025).

The vulnerability scanner Nessus provides a plugin with the ID 232841 (Cisco IOS XR Software Border Gateway Protocol Confederation DoS (cisco-sa-iosxr-bgp-dos-O7stePhX)), which helps to determine the existence of the flaw in a target environment.

Upgrading eliminates this vulnerability.

The vulnerability is also documented in the vulnerability database at Tenable (232841). Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Productinfo

Type

• Router Operating System

Vendor

• Cisco

Name

• IOS XR

Version

• 6.5.1
• 6.5.2
• 6.5.3
• 6.5.15
• 6.5.25
• 6.5.26
• 6.5.28
• 6.5.29
• 6.5.31
• 6.5.32
• 6.5.33
• 6.5.35
• 6.5.90
• 6.5.92
• 6.5.93
• 6.6.1
• 6.6.2
• 6.6.3
• 6.6.4
• 6.6.11
• 6.6.12
• 6.6.25
• 6.7.1
• 6.7.2
• 6.7.3
• 6.7.4
• 6.7.35
• 6.8.1
• 6.8.2
• 6.9.1
• 6.9.2
• 7.0.0
• 7.0.1
• 7.0.2
• 7.0.11
• 7.0.12
• 7.0.14
• 7.0.90
• 7.1.1
• 7.1.2
• 7.1.3
• 7.1.15
• 7.1.25
• 7.2.0
• 7.2.1
• 7.2.2
• 7.2.12
• 7.3.1
• 7.3.2
• 7.3.3
• 7.3.4
• 7.3.5
• 7.3.6
• 7.3.15
• 7.3.16
• 7.3.27
• 7.4.1
• 7.4.2
• 7.4.15
• 7.4.16
• 7.5.1
• 7.5.2
• 7.5.3
• 7.5.4
• 7.5.5
• 7.5.12
• 7.5.52
• 7.6.1
• 7.6.2
• 7.6.3
• 7.6.15
• 7.7.1
• 7.7.2
• 7.7.21
• 7.8.1
• 7.8.2
• 7.8.12
• 7.8.22
• 7.8.23
• 7.9.1
• 7.9.2
• 7.9.21
• 7.10.1
• 7.10.2
• 7.11.1
• 7.11.2
• 7.11.21
• 24.1.1
• 24.1.2
• 24.2.1
• 24.2.2
• 24.2.11
• 24.2.20

License

• commercial

Website

• Vendor: https://www.cisco.com/

CPE 2.3info

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Entryinfo

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

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