Cyber Resilience

CVE-2023-36833

Memory Safety in Juniper Junos Os Evolved 21.2 … 22.4

Memory Safety
Published
14 July 2023
Modified
21 November 2024
Patch / advisory
View advisory
CVSS Score v3.1 6.5
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:N/A:H
EPSS Score 0.0032 24th percentile
Risk Priority 49 floored blend · peak EPSS

Summary

CVE-2023-36833 is a medium-severity Use After Free (CWE-416) vulnerability in Juniper Junos Os Evolved. Its CVSS base score is 6.5 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Client Execution (T1203); ranked at the 24th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

EU & UK References

Vulnerability Data

A Use After Free vulnerability in the packet forwarding engine (PFE) of Juniper Networks Junos OS Evolved on PTX10001-36MR, and PTX10004, PTX10008, PTX10016 with LC1201/1202 allows an adjacent, unauthenticated attacker to cause a Denial of Service (DoS). The process 'aftman-bt'…

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will crash after multiple flaps on a multicast-only fast reroute (MoFRR) enabled interface. This will cause the respective FPC to stop forwarding traffic and it needs to be rebooted to restore the service. An indication that the system experienced this issue is the following log message: <date> <hostname> evo-aftmand-bt[<pid>]: [Error] jexpr_fdb: sanity check failed, ... , app_name L3 Mcast Routes This issue affects Juniper Networks Junos OS Evolved on PTX10001-36MR, PTX10004, PTX10008, PTX10016 with LC1201/1202: 21.2 version 21.2R1-EVO and later versions; 21.3 version 21.3R1-EVO and later versions; 21.4 versions prior to 21.4R3-S3-EVO; 22.1 version 22.1R1-EVO and later versions; 22.2 versions prior to 22.2R3-S2-EVO; 22.3 versions prior to 22.3R3-EVO; 22.4 versions prior to 22.4R1-S2-EVO, 22.4R2-EVO.

CWE(s)
CWE-416

Related Threats

MITRE ATT&CK Enterprise Techniques

T1203 Exploitation for Client Execution Execution
Adversaries may exploit software vulnerabilities in client applications to execute code.
attack.mitre.org →
T1068 Exploitation for Privilege Escalation Privilege Escalation
Adversaries may exploit software vulnerabilities in an attempt to elevate privileges.
attack.mitre.org →
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.
attack.mitre.org →
T1210 Exploitation of Remote Services Lateral Movement
Adversaries may exploit remote services to gain unauthorized access to internal systems once inside of a network.
attack.mitre.org →
T1212 Exploitation for Credential Access Credential Access
Adversaries may exploit software vulnerabilities in an attempt to collect credentials.
attack.mitre.org →
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2023-22402Same product: Juniper Junos Os Evolved
CVE-2026-21908Same product: Juniper Junos Os Evolved
CVE-2026-21921Same product: Juniper Junos Os Evolved
CVE-2024-39528Same product: Juniper Junos Os Evolved
CVE-2024-30386Same product: Juniper Junos Os Evolved
CVE-2023-28980Same product: Juniper Junos Os Evolved
CVE-2025-52946Same product: Juniper Junos Os Evolved
CVE-2024-30378Same vendor: Juniper
CVE-2023-28984Same vendor: Juniper
CVE-2025-26681Shared CWE-416

Affected Assets

juniper
junos os evolved
21.2, 21.3, 21.4, 22.1, 22.2

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

—

Detect
Catch it (NIST detect / respond)

—

Harden
Shrink the surface (DISA STIG)
  • 3 hardening rules · 3 OS baselines
Validate
Prove the fix (OWASP ASVS)
  • V1.4.3

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

SI-16 Memory Protection
addresses: CWE-416

Use-after-free exploits that achieve arbitrary code execution are blocked or significantly hardened by non-executable pages and ASLR.

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 incorporate memory-safety tooling and reviews that prevent most use-after-free defects.

ID.RA-01 partial match
prevents

Vulnerability identification processes can discover use-after-free issues via scanning or analysis but do not prevent their introduction.

PR.PS-02 partial match
prevents

Routine patching removes known use-after-free instances after they have been introduced in released software.

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.

A.8.29 Security testing in development and acceptance mostly match
finds

Security testing in development can detect use-after-free bugs before release.

A.8.25 Secure development life cycle partial match
prevents

Secure SDLC mandates memory-safety practices that reduce use-after-free defects.

A.8.26 Application security requirements partial match
prevents

Application security requirements can specify memory-management rules that mitigate use-after-free.

A.8.27 Secure system architecture and engineering principles partial match
prevents

Secure architecture principles include memory-safety design choices that limit use-after-free exposure.

A.8.28 Secure coding partial match
prevents

Secure coding standards directly prescribe avoidance of use-after-free patterns.

A.8.32 Change management partial match
prevents

Change-management processes help ensure memory-safety fixes are deployed consistently.

Hardening callouts derived

Configuration rules from DISA STIG baselines that bear on weaknesses of the type cited by this CVE. Each rule is shown with the relationship its mapping actually records, against the CWE it was authored against. Derived via CVE→CWE over `controls_xwalks` (authoritative rows only; rows rated `none` are excluded).

Oracle Linux 8 (1 rule)
  • V-248592 OL 8 must clear memory when it is freed to prevent use-after-free attacks. prevents CWE-416
RHEL 8 (1 rule)
  • V-230279 RHEL 8 must clear memory when it is freed to prevent use-after-free attacks. prevents CWE-416
RHEL 9 (1 rule)
  • V-257794 RHEL 9 must clear memory when it is freed to prevent use-after-free attacks. prevents CWE-416

References