{
    "CVE_data_meta": {
        "ASSIGNER": "sirt@juniper.net",
        "DATE_PUBLIC": "2021-10-13T16:00:00.000Z",
        "ID": "CVE-2021-31353",
        "STATE": "PUBLIC",
        "TITLE": "Junos OS and Junos OS Evolved: RPD core upon receipt of specific BGP update"
    },
    "affects": {
        "vendor": {
            "vendor_data": [
                {
                    "product": {
                        "product_data": [
                            {
                                "product_name": "Junos OS",
                                "version": {
                                    "version_data": [
                                        {
                                            "version_affected": "!<",
                                            "version_value": "19.3R3-S2"
                                        },
                                        {
                                            "version_affected": "=",
                                            "version_value": "19.3R3-S2"
                                        },
                                        {
                                            "version_affected": "=",
                                            "version_value": "19.4R3-S3"
                                        },
                                        {
                                            "version_affected": "!>=",
                                            "version_name": "20.1",
                                            "version_value": "20.1R1"
                                        },
                                        {
                                            "version_affected": "!<",
                                            "version_name": "20.2",
                                            "version_value": "20.2R2-S3"
                                        },
                                        {
                                            "version_affected": "<",
                                            "version_name": "20.2",
                                            "version_value": "20.2R3-S2"
                                        },
                                        {
                                            "version_affected": "!<",
                                            "version_name": "20.3",
                                            "version_value": "20.3R2"
                                        },
                                        {
                                            "version_affected": "<",
                                            "version_name": "20.3",
                                            "version_value": "20.3R3"
                                        },
                                        {
                                            "version_affected": "!<",
                                            "version_name": "20.4",
                                            "version_value": "20.4R2"
                                        },
                                        {
                                            "version_affected": "<",
                                            "version_name": "20.4",
                                            "version_value": "20.4R3"
                                        },
                                        {
                                            "version_affected": "<",
                                            "version_name": "21.1",
                                            "version_value": "21.1R2"
                                        }
                                    ]
                                }
                            },
                            {
                                "product_name": "Junos OS Evolved",
                                "version": {
                                    "version_data": [
                                        {
                                            "version_affected": "<",
                                            "version_value": "20.4R2-S3-EVO, 20.4R3-EVO"
                                        },
                                        {
                                            "version_affected": "<",
                                            "version_name": "21.1-EVO",
                                            "version_value": "21.1R2-EVO"
                                        },
                                        {
                                            "version_affected": "<",
                                            "version_name": "21.2-EVO",
                                            "version_value": "21.2R2-EVO"
                                        }
                                    ]
                                }
                            }
                        ]
                    },
                    "vendor_name": "Juniper Networks"
                }
            ]
        }
    },
    "configuration": [
        {
            "lang": "eng",
            "value": "This issue can occur when multipath is enabled:\n\n  routing-instance <vrf> routing-options multipath\n\nand one of the following two TTL propagation options (but not both) are enabled:\n\n  protocols mpls no-propagate-ttl\n  routing-instance <vrf> no-vrf-propagate-ttl\n"
        }
    ],
    "data_format": "MITRE",
    "data_type": "CVE",
    "data_version": "4.0",
    "description": {
        "description_data": [
            {
                "lang": "eng",
                "value": "An Improper Handling of Exceptional Conditions vulnerability in Juniper Networks Junos OS and Junos OS Evolved allows an attacker to inject a specific BGP update, causing the routing protocol daemon (RPD) to crash and restart, leading to a Denial of Service (DoS). Continued receipt and processing of the BGP update will create a sustained Denial of Service (DoS) condition. This issue affects very specific versions of Juniper Networks Junos OS: 19.3R3-S2; 19.4R3-S3; 20.2 versions 20.2R2-S3 and later, prior to 20.2R3-S2; 20.3 versions 20.3R2 and later, prior to 20.3R3; 20.4 versions 20.4R2 and later, prior to 20.4R3; 21.1 versions prior to 21.1R2. Juniper Networks Junos OS 20.1 is not affected by this issue. This issue also affects Juniper Networks Junos OS Evolved: All versions prior to 20.4R2-S3-EVO, 20.4R3-EVO; 21.1-EVO versions prior to 21.1R2-EVO; 21.2-EVO versions prior to 21.2R2-EVO."
            }
        ]
    },
    "exploit": [
        {
            "lang": "eng",
            "value": "Juniper SIRT is not aware of any malicious exploitation of this vulnerability."
        }
    ],
    "generator": {
        "engine": "Vulnogram 0.0.9"
    },
    "impact": {
        "cvss": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "HIGH",
            "baseScore": 7.5,
            "baseSeverity": "HIGH",
            "confidentialityImpact": "NONE",
            "integrityImpact": "NONE",
            "privilegesRequired": "NONE",
            "scope": "UNCHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
            "version": "3.1"
        }
    },
    "problemtype": {
        "problemtype_data": [
            {
                "description": [
                    {
                        "lang": "eng",
                        "value": "CWE-755 Improper Handling of Exceptional Conditions"
                    }
                ]
            }
        ]
    },
    "references": {
        "reference_data": [
            {
                "name": "https://kb.juniper.net/JSA11218",
                "refsource": "CONFIRM",
                "url": "https://kb.juniper.net/JSA11218"
            }
        ]
    },
    "solution": [
        {
            "lang": "eng",
            "value": "The following software releases have been updated to resolve this specific issue: \n\nJunos OS 18.4R2-S9, 19.1R3-S7, 19.3R3-S3, 19.4R1-S4, 19.4R3-S4, 20.1R3, 20.2R3-S2, 20.3R3, 20.4R3, 21.1R2, 21.2R1, 21.2R2, 21.3R1, and all subsequent releases.\n\nJunos OS Evolved 20.4R2-S3-EVO, 20.4R3-EVO, 21.1R2-EVO, 21.2R2-EVO, 21.3R1-EVO, and all subsequent releases.\n\nNote: Only those releases listed in the PROBLEM section above are affected.  This fix has also been proactively committed into other releases that are not vulnerable to this issue."
        }
    ],
    "source": {
        "advisory": "JSA11218",
        "defect": [
            "1595165"
        ],
        "discovery": "USER"
    },
    "work_around": [
        {
            "lang": "eng",
            "value": "This issue can be mitigated in two ways:\n\n1) ensure that TTL propagation is either enabled or disabled in both places below:\n  protocols mpls no-propagate-ttl\n  routing-instance <vrf> no-vrf-propagate-ttl\n\n2) Disable multipath:\n  routing-instance <vrf> routing-options multipath \n"
        }
    ]
}