Raw vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:HSummary
CVE-2025-20115 is a high-severity Classic Buffer Overflow (CWE-120) vulnerability in Cisco Ios Xr. Its CVSS base score is 8.6 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Privilege Escalation (T1068); ranked in the top 44% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.
The strongest mitigations our analysis identified map to SA-11 (Developer Testing and Evaluation) and SI-10 (Information Input Validation) — see the control section below for these in your framework.
Deeper analysis AI-assisted summary
Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.
A vulnerability in the confederation implementation of the Border Gateway Protocol (BGP) in Cisco IOS XR Software stems from memory corruption that occurs when processing a BGP update containing an AS_CONFED_SEQUENCE attribute with exactly 255 autonomous system numbers. The affected component is the BGP process within IOS XR, and the flaw is tracked under CWE-120 with a CVSS score of 8.6.
An unauthenticated remote attacker who controls a BGP confederation speaker inside the same autonomous system as the target device can send a specially crafted BGP update message to trigger the corruption. The same outcome can occur through network topology that naturally expands the AS_CONFED_SEQUENCE attribute to 255 or more entries. Successful exploitation restarts the BGP process and produces a denial-of-service condition.
The Cisco Security Advisory cisco-sa-iosxr-bgp-dos-O7stePhX and related references such as the APNIC blog on BGP AS-path manipulation provide official guidance on mitigation steps and software updates. The associated EPSS score remains low, with a current value of 0.0137 and a peak of 0.0177, indicating no significant post-disclosure increase in observed exploitation activity.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2025-7287
Vulnerability Data
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…
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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.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Control response
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V5.2.1
Mitigating Controls (NIST 800-53 r5) AI
Developer testing and analysis can find missing size checks before deployment.
Input validation directly enforces size checks before buffer copies.
Engineering principles require bounds checking and safe buffer handling in design.
Memory protection limits the impact of an overflow once it occurs.
Mitigating Controls (NIST CSF 2.0) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.
Secure development practices directly enforce bounds checking and input validation that prevent classic buffer overflows.
Vulnerability identification processes such as code review or scanning detect classic buffer overflows before exploitation.
Routine patching replaces vulnerable code containing unchecked buffer copies with corrected versions.
Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.
Secure coding directly requires bounds-checked memory operations, addressing the root cause of CWE-120.
Security testing in development and acceptance can detect buffer overflows through fuzzing and static analysis, though it does not prevent them at the source.
Secure development life cycle mandates processes that can include input validation and bounds checking to prevent buffer overflows.
Application security requirements can specify input-size validation and safe buffer handling to mitigate classic buffer overflows.
Secure system architecture and engineering principles promote defensive coding patterns that reduce the likelihood of unchecked buffer copies.