CVE-2021-41115

{"containers": {"cna": {"affected": [{"product": "zulip", "vendor": "zulip", "versions": [{"status": "affected", "version": "< 4.7"}]}], "descriptions": [{"lang": "en", "value": "Zulip is an open source team chat server. In affected versions Zulip allows organization administrators on a server to configure \"linkifiers\" that automatically create links from messages that users send, detected via arbitrary regular expressions. Malicious organization administrators could subject the server to a denial-of-service via regular expression complexity attacks; most simply, by configuring a quadratic-time regular expression in a linkifier, and sending messages that exploited it. A regular expression attempted to parse the user-provided regexes to verify that they were safe from ReDoS -- this was both insufficient, as well as _itself_ subject to ReDoS if the organization administrator entered a sufficiently complex invalid regex. Affected users should [upgrade to the just-released Zulip 4.7](https://zulip.readthedocs.io/en/latest/production/upgrade-or-modify.html#upgrading-to-a-release), or [`main`](https://zulip.readthedocs.io/en/latest/production/upgrade-or-modify.html#upgrading-from-a-git-repository)."}], "metrics": [{"cvssV3_1": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "LOW", "baseScore": 4.3, "baseSeverity": "MEDIUM", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "privilegesRequired": "LOW", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L", "version": "3.1"}}], "problemTypes": [{"descriptions": [{"cweId": "CWE-400", "description": "CWE-400: Uncontrolled Resource Consumption", "lang": "en", "type": "CWE"}]}, {"descriptions": [{"cweId": "CWE-1333", "description": "CWE-1333: Inefficient Regular Expression Complexity", "lang": "en", "type": "CWE"}]}], "providerMetadata": {"dateUpdated": "2021-10-07T22:20:13.000Z", "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "shortName": "GitHub_M"}, "references": [{"tags": ["x_refsource_CONFIRM"], "url": "https://github.com/zulip/zulip/security/advisories/GHSA-4h36-mqfq-42jg"}, {"tags": ["x_refsource_MISC"], "url": "https://github.com/zulip/zulip/commit/e2d303c1bb5f538d17dc3d9134bc8858bdece781"}, {"tags": ["x_refsource_MISC"], "url": "https://securitylab.github.com/advisories/GHSL-2021-118-zulip-zulip/"}], "source": {"advisory": "GHSA-4h36-mqfq-42jg", "discovery": "UNKNOWN"}, "title": "Regular expression denial-of-service in Zulip", "x_legacyV4Record": {"CVE_data_meta": {"ASSIGNER": "security-advisories@github.com", "ID": "CVE-2021-41115", "STATE": "PUBLIC", "TITLE": "Regular expression denial-of-service in Zulip"}, "affects": {"vendor": {"vendor_data": [{"product": {"product_data": [{"product_name": "zulip", "version": {"version_data": [{"version_value": "< 4.7"}]}}]}, "vendor_name": "zulip"}]}}, "data_format": "MITRE", "data_type": "CVE", "data_version": "4.0", "description": {"description_data": [{"lang": "eng", "value": "Zulip is an open source team chat server. In affected versions Zulip allows organization administrators on a server to configure \"linkifiers\" that automatically create links from messages that users send, detected via arbitrary regular expressions. Malicious organization administrators could subject the server to a denial-of-service via regular expression complexity attacks; most simply, by configuring a quadratic-time regular expression in a linkifier, and sending messages that exploited it. A regular expression attempted to parse the user-provided regexes to verify that they were safe from ReDoS -- this was both insufficient, as well as _itself_ subject to ReDoS if the organization administrator entered a sufficiently complex invalid regex. Affected users should [upgrade to the just-released Zulip 4.7](https://zulip.readthedocs.io/en/latest/production/upgrade-or-modify.html#upgrading-to-a-release), or [`main`](https://zulip.readthedocs.io/en/latest/production/upgrade-or-modify.html#upgrading-from-a-git-repository)."}]}, "impact": {"cvss": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "LOW", "baseScore": 4.3, "baseSeverity": "MEDIUM", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "privilegesRequired": "LOW", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L", "version": "3.1"}}, "problemtype": {"problemtype_data": [{"description": [{"lang": "eng", "value": "CWE-400: Uncontrolled Resource Consumption"}]}, {"description": [{"lang": "eng", "value": "CWE-1333: Inefficient Regular Expression Complexity"}]}]}, "references": {"reference_data": [{"name": "https://github.com/zulip/zulip/security/advisories/GHSA-4h36-mqfq-42jg", "refsource": "CONFIRM", "url": "https://github.com/zulip/zulip/security/advisories/GHSA-4h36-mqfq-42jg"}, {"name": "https://github.com/zulip/zulip/commit/e2d303c1bb5f538d17dc3d9134bc8858bdece781", "refsource": "MISC", "url": "https://github.com/zulip/zulip/commit/e2d303c1bb5f538d17dc3d9134bc8858bdece781"}, {"name": "https://securitylab.github.com/advisories/GHSL-2021-118-zulip-zulip/", "refsource": "MISC", "url": "https://securitylab.github.com/advisories/GHSL-2021-118-zulip-zulip/"}]}, "source": {"advisory": "GHSA-4h36-mqfq-42jg", "discovery": "UNKNOWN"}}}, "adp": [{"providerMetadata": {"orgId": "af854a3a-2127-422b-91ae-364da2661108", "shortName": "CVE", "dateUpdated": "2024-08-04T02:59:31.570Z"}, "title": "CVE Program Container", "references": [{"tags": ["x_refsource_CONFIRM", "x_transferred"], "url": "https://github.com/zulip/zulip/security/advisories/GHSA-4h36-mqfq-42jg"}, {"tags": ["x_refsource_MISC", "x_transferred"], "url": "https://github.com/zulip/zulip/commit/e2d303c1bb5f538d17dc3d9134bc8858bdece781"}, {"tags": ["x_refsource_MISC", "x_transferred"], "url": "https://securitylab.github.com/advisories/GHSL-2021-118-zulip-zulip/"}]}]}, "cveMetadata": {"assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "assignerShortName": "GitHub_M", "cveId": "CVE-2021-41115", "datePublished": "2021-10-07T22:20:13.000Z", "dateReserved": "2021-09-15T00:00:00.000Z", "dateUpdated": "2024-08-04T02:59:31.570Z", "state": "PUBLISHED"}, "dataType": "CVE_RECORD", "dataVersion": "5.1"}

{}

{"affected": [{"affectedData": [{"product": "zulip", "vendor": "zulip", "versions": [{"status": "affected", "version": "< 4.7"}]}], "source": "security-advisories@github.com"}], "configurations": [{"nodes": [{"cpeMatch": [{"criteria": "cpe:2.3:a:zulip:zulip:*:*:*:*:*:*:*:*", "matchCriteriaId": "C12C5D8B-FC65-4A14-B843-106963C0AEA8", "versionEndExcluding": "4.7", "vulnerable": true}], "negate": false, "operator": "OR"}]}], "cveTags": [], "descriptions": [{"lang": "en", "value": "Zulip is an open source team chat server. In affected versions Zulip allows organization administrators on a server to configure \"linkifiers\" that automatically create links from messages that users send, detected via arbitrary regular expressions. Malicious organization administrators could subject the server to a denial-of-service via regular expression complexity attacks; most simply, by configuring a quadratic-time regular expression in a linkifier, and sending messages that exploited it. A regular expression attempted to parse the user-provided regexes to verify that they were safe from ReDoS -- this was both insufficient, as well as _itself_ subject to ReDoS if the organization administrator entered a sufficiently complex invalid regex. Affected users should [upgrade to the just-released Zulip 4.7](https://zulip.readthedocs.io/en/latest/production/upgrade-or-modify.html#upgrading-to-a-release), or [`main`](https://zulip.readthedocs.io/en/latest/production/upgrade-or-modify.html#upgrading-from-a-git-repository)."}, {"lang": "es", "value": "Zulip es un servidor de chat de equipo de c\u00f3digo abierto. En las versiones afectadas, Zulip permite a los administradores de la organizaci\u00f3n en un servidor configurar \"linkifiers\" que crean autom\u00e1ticamente enlaces a partir de los mensajes que env\u00edan los usuarios, detectados por medio de expresiones regulares arbitrarias. Los administradores de organizaciones maliciosos pod\u00edan someter al servidor a una denegaci\u00f3n de servicio por medio de ataques de complejidad de expresiones regulares; m\u00e1s sencillo, al configurar una expresi\u00f3n regular de tiempo cuadr\u00e1tico en un enlazador, y enviando mensajes que la explotaran. Una expresi\u00f3n regular intentaba analizar las expresiones regulares proporcionadas por el usuario para verificar que estaban a salvo de ReDoS - esto era insuficiente, as\u00ed como _suficiente para someter al servidor a ReDoS si el administrador de la organizaci\u00f3n introduc\u00eda una expresi\u00f3n regular no v\u00e1lida suficientemente compleja. Los usuarios afectados deber\u00edan [actualizar a la reci\u00e9n estrenada Zulip versi\u00f3n 4.7](https://zulip.readthedocs.io/en/latest/production/upgrade-or-modify.html#upgrading-to-a-release), o [`main`](https://zulip.readthedocs.io/en/latest/production/upgrade-or-modify.html#upgrading-from-a-git-repository)"}], "id": "CVE-2021-41115", "lastModified": "2026-06-17T04:07:54.053", "metrics": {"cvssMetricV2": [{"acInsufInfo": false, "baseSeverity": "MEDIUM", "cvssData": {"accessComplexity": "LOW", "accessVector": "NETWORK", "authentication": "SINGLE", "availabilityImpact": "PARTIAL", "baseScore": 4.0, "confidentialityImpact": "NONE", "integrityImpact": "NONE", "vectorString": "AV:N/AC:L/Au:S/C:N/I:N/A:P", "version": "2.0"}, "exploitabilityScore": 8.0, "impactScore": 2.9, "obtainAllPrivilege": false, "obtainOtherPrivilege": false, "obtainUserPrivilege": false, "source": "nvd@nist.gov", "type": "Primary", "userInteractionRequired": false}], "cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "LOW", "baseScore": 4.3, "baseSeverity": "MEDIUM", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "privilegesRequired": "LOW", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L", "version": "3.1"}, "exploitabilityScore": 2.8, "impactScore": 1.4, "source": "security-advisories@github.com", "type": "Secondary"}, {"cvssData": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "HIGH", "baseScore": 6.5, "baseSeverity": "MEDIUM", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "privilegesRequired": "LOW", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H", "version": "3.1"}, "exploitabilityScore": 2.8, "impactScore": 3.6, "source": "nvd@nist.gov", "type": "Primary"}]}, "published": "2021-10-07T23:15:08.027", "references": [{"source": "security-advisories@github.com", "tags": ["Patch", "Third Party Advisory"], "url": "https://github.com/zulip/zulip/commit/e2d303c1bb5f538d17dc3d9134bc8858bdece781"}, {"source": "security-advisories@github.com", "tags": ["Patch", "Third Party Advisory"], "url": "https://github.com/zulip/zulip/security/advisories/GHSA-4h36-mqfq-42jg"}, {"source": "security-advisories@github.com", "tags": ["Exploit", "Third Party Advisory"], "url": "https://securitylab.github.com/advisories/GHSL-2021-118-zulip-zulip/"}, {"source": "af854a3a-2127-422b-91ae-364da2661108", "tags": ["Patch", "Third Party Advisory"], "url": "https://github.com/zulip/zulip/commit/e2d303c1bb5f538d17dc3d9134bc8858bdece781"}, {"source": "af854a3a-2127-422b-91ae-364da2661108", "tags": ["Patch", "Third Party Advisory"], "url": "https://github.com/zulip/zulip/security/advisories/GHSA-4h36-mqfq-42jg"}, {"source": "af854a3a-2127-422b-91ae-364da2661108", "tags": ["Exploit", "Third Party Advisory"], "url": "https://securitylab.github.com/advisories/GHSL-2021-118-zulip-zulip/"}], "sourceIdentifier": "security-advisories@github.com", "vulnStatus": "Modified", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-400"}, {"lang": "en", "value": "CWE-1333"}], "source": "security-advisories@github.com", "type": "Secondary"}, {"description": [{"lang": "en", "value": "CWE-1333"}], "source": "nvd@nist.gov", "type": "Primary"}]}

{}

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