CVE-2024-20390
Cisco Ios Xr ≤ 24.1.2
Raw vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:LCVSS and EPSS are reproduced from their sources (NVD, FIRST EPSS). Risk Priority is our own derived reading, not an NVD score.
Summary
CVE-2024-20390 is a medium-severity Improper Verification of Source of a Communication Channel (CWE-940) vulnerability in Cisco Ios Xr. Its CVSS base score is 5.3 (Medium).
Operationally, exploitation aligns with the MITRE ATT&CK technique LSASS Memory (T1003.001); ranked at the 36th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.
The strongest mitigations our analysis identified map to AC-17 (Remote Access) and IA-3 (Device Identification and Authentication) — see the control section below for these in your framework.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2024-18105
Vulnerability Data
A vulnerability in the Dedicated XML Agent feature of Cisco IOS XR Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) on XML TCP listen port 38751. This vulnerability is due to a lack of…
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proper error validation of ingress XML packets. An attacker could exploit this vulnerability by sending a sustained, crafted stream of XML traffic to a targeted device. A successful exploit could allow the attacker to cause XML TCP port 38751 to become unreachable while the attack traffic persists.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Control response
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V3.5.3V10.6.2V15.2.4
Mitigating Controls (NIST 800-53 r5) AI
IA-3 requires unique identification and authentication of devices before any communication channel is established, directly stopping acceptance of unverified origins.
AC-17 mandates documented restrictions and authentication requirements for remote access, blocking channels whose origins are not properly verified.
SC-23 protects session authenticity, ensuring the source of an established communication channel is verified and cannot be spoofed.
SC-7 enforces monitoring and control at external and key internal interfaces, preventing channels from unverified sources via boundary rules.
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.
Authentication of users/services/hardware directly enforces source verification for communication channels.
Verifying identity assertions prevents spoofed channel origins but does not cover all channel-establishment scenarios.
Network protections reduce unauthorized channel usage but do not specifically require origin verification at channel setup.
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.
Network security controls enforce source verification and channel authentication for incoming communications.
Security of network services includes validating the origin of service requests and connections.
A.8.24 mandates proper use of cryptography (algorithms, key management, protection of data in transit/storage) but has no bearing on whether a product correctly verifies the origin of an incoming communication channel; the weakness can still be present and exploited regardless of cryptographic controls.
A.8.26 requires identifying and specifying requirements for resilience against malicious attacks (explicitly naming SQL injection) plus input validation, authentication, segregation of access, output controls, and cryptography; these can address origin verification for expected channels in some (but not all) application designs, leaving a bounded remainder where the weakness is still exploitable.
Secure coding practices can prevent improper source verification if explicitly required.
A.8.5 chooses and strengthens authentication techniques for claimed identities at log-on; it has no bearing on whether an established channel's origin is verified after the fact, so the weakness can still be exploited