Security Resilience

CVE-2024-20319

Cisco Ios Xr 5.2.0 … 7.9.21

Published
13 March 2024
Modified
17 June 2026
Patch / advisory
CVSS Score v3.1 4.3
Click a component to see what it means
Raw vectorCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
EPSS Score 0.0025 15th percentile
Risk Priority 36 floored blend · peak EPSS

CVSS and EPSS are reproduced from their sources (NVD, FIRST EPSS). Risk Priority is our own derived reading, not an NVD score.

Summary

CVE-2024-20319 is a medium-severity Improper Access Control (CWE-284) vulnerability in Cisco Ios Xr. Its CVSS base score is 4.3 (Medium).

Operationally, ranked at the 15th 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-3 (Access Enforcement) and AC-4 (Information Flow Enforcement) — see the control section below for these in your framework.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

A vulnerability in the UDP forwarding code of Cisco IOS XR Software could allow an unauthenticated, adjacent attacker to bypass configured management plane protection policies and access the Simple Network Management Plane (SNMP) server of an affected device. This vulnerability…

more

is due to incorrect UDP forwarding programming when using SNMP with management plane protection. An attacker could exploit this vulnerability by attempting to perform an SNMP operation using broadcast as the destination address that could be processed by an affected device that is configured with an SNMP server. A successful exploit could allow the attacker to communicate to the device on the configured SNMP ports. Although an unauthenticated attacker could send UDP datagrams to the configured SNMP port, only an authenticated user can retrieve or modify data using SNMP requests.

CWE(s)

Related Threats

CVEs Like This One

CVE-2023-20191Same product: Cisco Ios Xr
CVE-2024-20343Same product: Cisco Ios Xr
CVE-2025-20144Same product: Cisco Ios Xr
CVE-2024-20322Same product: Cisco Ios Xr
CVE-2026-20167Same vendor: Cisco
CVE-2026-20007Same vendor: Cisco
CVE-2025-20335Same vendor: Cisco
CVE-2024-20283Same vendor: Cisco
CVE-2024-20325Same vendor: Cisco
CVE-2024-20465Same vendor: Cisco

Affected Assets

cisco
ios xr
5.2.0, 5.2.1, 5.2.2, 5.2.3, 5.2.4

Mitigating Controls

Mitigating Controls (NIST 800-53 r5) AI

Directly enforces approved authorizations for logical access, stopping unauthorized actors from reaching resources.

Enforces flow-control policies that restrict information movement between subjects and objects.

Documents duties and assigns access so that no single account can bypass intended restrictions.

Limits each account to the minimum privileges needed, reducing the chance of unauthorized access.

Defines account types, assigns/removes access, and reviews accounts to ensure only authorized actors can reach resources.

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.

blocks

A.5.1 only requires that an information security policy and topic-specific policies (including on access control) exist and are reviewed; it does not itself enforce, implement or act on any access restriction, so the weakness can still be exploited (per the owner's explicit rule that governance/dependency clauses score none on effect verbs).

blocks

A.5.15 directly mandates determining requirements, defining/implementing topic-specific access control policy+rules (with explicit references to 8.3, 5.16, 5.18), and enforcing authorized access while preventing unauthorized access, which squarely stops exploitation of most CWE-284 instances; the bounded remainder is the physical slice (explicitly delegated to 7.2-7.4) plus any second-order defects like path traversal that are not authorization decisions.

blocks

A.5.16's identity lifecycle (unique binding, timely disable/remove, no duplicates, oversight of shared/non-human) directly stops most improper access by ensuring the actor in an access decision is correctly identified and authorized; the bounded remainder is non-identity mechanisms in CWE-284 such as path traversal or CSRF that do not turn on actor identity at all.

blocks

A.5.18 directly governs the provisioning, review, adjustment and timely revocation of both physical and logical access rights per business rules, segregation of duties and risk-evaluated changes/terminations; this stops most unauthorized-actor exploitation paths named by CWE-284, with a bounded remainder (e.g. path-traversal or CSRF cases that are not authorization decisions at all)

blocks

A.5.2 defines and assigns roles/responsibilities for protection of information and risk acceptance; it does not itself enforce any access decision and cannot stop exploitation of improper access control (per the owner's labeling rule: governance/dependency clauses do not score on prevent/mitigate verbs)

finds

Ongoing audits and performance reviews of suppliers detect and correct situations where access controls or privilege assignments are weaker than contractually required, limiting an attacker's ability to exploit improper access control in the supplier's environment.

Hardening callouts derived

DISA STIG baselines are authored against specific weaknesses. Where this CVE cites a broad weakness class, the mapping is not asserted at that abstraction (owner ruling, 2026-09-25: grade only at Base and below), so no rule is shown here rather than a rule shown against the wrong grain.

  • No fine-grained STIG row for CWE-284, a pillar-level weakness. Rules are authored against its narrower children: CWE-749, CWE-1220.

References