Cyber Resilience

CVE-2024-21618

Memory Safety in Juniper Junos 21.4 … 23.2

Published
12 April 2024
Modified
06 February 2025
Patch / advisory
CVSS Score v4 7.1
Click a component to see what it means
Raw vectorCVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:L/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
EPSS Score 0.0030 22th percentile
Risk Priority 35 floored blend · peak EPSS

Summary

CVE-2024-21618 is a high-severity Access of Memory Location After End of Buffer (CWE-788) vulnerability in Juniper Junos. Its CVSS base score is 7.1 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Privilege Escalation (T1068); ranked at the 22th 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 SA-11 (Developer Testing and Evaluation) and SA-8 (Security and Privacy Engineering Principles) — see the control section below for these in your framework.

EU & UK References

Vulnerability Data

An Access of Memory Location After End of Buffer vulnerability in the Layer-2 Control Protocols Daemon (l2cpd) of Juniper Networks Junos OS and Junos OS Evolved allows an adjacent, unauthenticated attacker to cause Denial of Service (DoS). On all Junos…

more

OS and Junos OS Evolved platforms, when LLDP is enabled on a specific interface, and a malformed LLDP packet is received, l2cpd crashes and restarts. The impact of the l2cpd crash is reinitialization of STP protocols (RSTP, MSTP or VSTP), and MVRP and ERP. Also, if any services depend on LLDP state (like PoE or VoIP device recognition), then these will also be affected. This issue affects: Junos OS: * from 21.4 before 21.4R3-S4, * from 22.1 before 22.1R3-S4, * from 22.2 before 22.2R3-S2, * from 22.3 before 22.3R2-S2, 22.3R3-S1, * from 22.4 before 22.4R3, * from 23.2 before 23.2R2. Junos OS Evolved: * from 21.4-EVO before 21.4R3-S5-EVO, * from 22.1-EVO before 22.1R3-S4-EVO, * from 22.2-EVO before 22.2R3-S2-EVO, * from 22.3-EVO before 22.3R2-S2-EVO, 22.3R3-S1-EVO, * from 22.4-EVO before 22.4R3-EVO, * from 23.2-EVO before 23.2R2-EVO. This issue does not affect: * Junos OS versions prior to 21.4R1; * Junos OS Evolved versions prior to 21.4R1-EVO.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise Techniques

T1068 Exploitation for Privilege Escalation Privilege Escalation
Adversaries may exploit software vulnerabilities in an attempt to elevate privileges.
T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
T1203 Exploitation for Client Execution Execution
Adversaries may exploit software vulnerabilities in client applications to execute code.
T1210 Exploitation of Remote Services Lateral Movement
Adversaries may exploit remote services to gain unauthorized access to internal systems once inside of a network.
T1212 Exploitation for Credential Access Credential Access
Adversaries may exploit software vulnerabilities in an attempt to collect credentials.
T1211 Exploitation for Stealth Stealth
Adversaries may exploit vulnerabilities to evade detection by hiding activity, suppressing logging, or operating within trusted or unmonitored components.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2024-39516Same product: Juniper Junos
CVE-2025-21598Same product: Juniper Junos
CVE-2025-21600Same product: Juniper Junos
CVE-2023-22401Same product: Juniper Junos
CVE-2023-22398Same product: Juniper Junos
CVE-2024-21596Same product: Juniper Junos
CVE-2023-44178Same product: Juniper Junos
CVE-2024-30394Same product: Juniper Junos
CVE-2023-44197Same product: Juniper Junos
CVE-2023-44177Same product: Juniper Junos

Affected Assets

juniper
junos
21.4, 22.1, 22.2, 22.3, 22.4
juniper
junos os evolved
21.4, 22.1, 22.2, 22.3, 22.4

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

Detect
Catch it (NIST detect / respond)

Harden
Shrink the surface (DISA STIG)

Validate
Prove the fix (OWASP ASVS)
  • V1.4.1

Mitigating Controls (NIST 800-53 r5) AI

Developer testing and evaluation can discover buffer-end violations through static analysis, fuzzing, or dynamic bounds checks.

Security engineering principles require bounds checking, safe arithmetic, and language choices that structurally eliminate post-end buffer accesses.

Process isolation confines the effects of an out-of-bounds read to the compromised process.

Input validation enforces bounds on lengths and indices before buffer operations, stopping out-of-bounds accesses after the end of the buffer.

Memory protection mechanisms limit the effects of post-end buffer accesses by blocking unauthorized code execution or data corruption.

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.

PR.PS-06 mostly match
prevents

Secure SDLC practices directly require bounds checking and input validation that prevent out-of-bounds buffer accesses.

ID.RA-01 partial match
prevents

Vulnerability scanning and recording can discover instances of out-of-bounds reads after code is deployed.

PR.PS-02 partial match
prevents

Routine patching replaces vulnerable code containing out-of-bounds read flaws.

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.

finds

Security testing in development can detect buffer-overrun defects before release.

A.8.15 Logging partial match
finds

Logging can record evidence of an out-of-bounds read but does not prevent the weakness itself.

prevents

Secure development life cycle includes buffer-handling practices that reduce out-of-bounds accesses.

prevents

Application security requirements can mandate bounds checking and safe memory APIs.

prevents

Secure architecture principles discourage unsafe pointer arithmetic and unbounded buffers.

prevents

Secure coding standards directly forbid writing or reading past buffer ends.

References