{
    "dataType": "CVE_RECORD",
    "dataVersion": "5.1",
    "cveMetadata": {
        "cveId": "CVE-2023-2911",
        "assignerOrgId": "404fd4d2-a609-4245-b543-2c944a302a22",
        "state": "PUBLISHED",
        "assignerShortName": "isc",
        "dateReserved": "2023-05-26T11:20:45.872Z",
        "datePublished": "2023-06-21T16:26:36.587Z",
        "dateUpdated": "2024-08-02T06:41:03.760Z"
    },
    "containers": {
        "cna": {
            "providerMetadata": {
                "orgId": "404fd4d2-a609-4245-b543-2c944a302a22",
                "shortName": "isc",
                "dateUpdated": "2023-06-21T16:26:36.587Z"
            },
            "title": "Exceeding the recursive-clients quota may cause named to terminate unexpectedly when stale-answer-client-timeout is set to 0",
            "datePublic": "2023-06-21T00:00:00Z",
            "affected": [
                {
                    "vendor": "ISC",
                    "product": "BIND 9",
                    "versions": [
                        {
                            "version": "9.16.33",
                            "lessThanOrEqual": "9.16.41",
                            "status": "affected",
                            "versionType": "custom"
                        },
                        {
                            "version": "9.18.7",
                            "lessThanOrEqual": "9.18.15",
                            "status": "affected",
                            "versionType": "custom"
                        },
                        {
                            "version": "9.16.33-S1",
                            "lessThanOrEqual": "9.16.41-S1",
                            "status": "affected",
                            "versionType": "custom"
                        },
                        {
                            "version": "9.18.11-S1",
                            "lessThanOrEqual": "9.18.15-S1",
                            "status": "affected",
                            "versionType": "custom"
                        }
                    ],
                    "defaultStatus": "unaffected"
                }
            ],
            "metrics": [
                {
                    "cvssV3_1": {
                        "version": "3.1",
                        "attackVector": "NETWORK",
                        "attackComplexity": "LOW",
                        "privilegesRequired": "NONE",
                        "userInteraction": "NONE",
                        "scope": "UNCHANGED",
                        "confidentialityImpact": "NONE",
                        "integrityImpact": "NONE",
                        "availabilityImpact": "HIGH",
                        "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
                        "baseScore": 7.5,
                        "baseSeverity": "HIGH"
                    }
                }
            ],
            "descriptions": [
                {
                    "lang": "en",
                    "value": "If the `recursive-clients` quota is reached on a BIND 9 resolver configured with both `stale-answer-enable yes;` and `stale-answer-client-timeout 0;`, a sequence of serve-stale-related lookups could cause `named` to loop and terminate unexpectedly due to a stack overflow.\nThis issue affects BIND 9 versions 9.16.33 through 9.16.41, 9.18.7 through 9.18.15, 9.16.33-S1 through 9.16.41-S1, and 9.18.11-S1 through 9.18.15-S1."
                }
            ],
            "impacts": [
                {
                    "descriptions": [
                        {
                            "lang": "en",
                            "value": "By sending specific queries to the resolver, an attacker can cause `named` to terminate unexpectedly."
                        }
                    ]
                }
            ],
            "workarounds": [
                {
                    "lang": "en",
                    "value": "Setting `stale-answer-client-timeout` to `off` or to a non-zero value prevents the issue.\n\nUsers of versions 9.18.10, 9.16.36, 9.16.36-S1 or older who are unable to upgrade should set `stale-answer-client-timeout` to `off`; using a non-zero value with these older versions leaves `named` vulnerable to CVE-2022-3924.\n\nAlthough it is possible to set the `recursive-clients` limit to a high number to reduce the likelihood of this scenario, this is not recommended; the limit on `recursive-clients` is important for preventing exhaustion of server resources. The limit cannot be disabled entirely."
                }
            ],
            "exploits": [
                {
                    "lang": "en",
                    "value": "This flaw was discovered in internal testing. We are not aware of any active exploits."
                }
            ],
            "solutions": [
                {
                    "lang": "en",
                    "value": "Upgrade to the patched release most closely related to your current version of BIND 9: 9.16.42, 9.18.16, 9.16.42-S1, or 9.18.16-S1."
                }
            ],
            "references": [
                {
                    "url": "https://kb.isc.org/docs/cve-2023-2911",
                    "name": "CVE-2023-2911",
                    "tags": [
                        "vendor-advisory"
                    ]
                },
                {
                    "url": "http://www.openwall.com/lists/oss-security/2023/06/21/6"
                },
                {
                    "url": "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/U3K6AJK7RRSR53HRF5GGKPA6PDUDWOD2/"
                },
                {
                    "url": "https://www.debian.org/security/2023/dsa-5439"
                },
                {
                    "url": "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/SEFCEVCTYEMKTWA7V7EYPI5YQQ4JWDLI/"
                },
                {
                    "url": "https://security.netapp.com/advisory/ntap-20230703-0010/"
                }
            ],
            "source": {
                "discovery": "INTERNAL"
            }
        },
        "adp": [
            {
                "providerMetadata": {
                    "orgId": "af854a3a-2127-422b-91ae-364da2661108",
                    "shortName": "CVE",
                    "dateUpdated": "2024-08-02T06:41:03.760Z"
                },
                "title": "CVE Program Container",
                "references": [
                    {
                        "url": "https://kb.isc.org/docs/cve-2023-2911",
                        "name": "CVE-2023-2911",
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                        "url": "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/U3K6AJK7RRSR53HRF5GGKPA6PDUDWOD2/",
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    }
}