{"id":"CVE-2025-21591","state":"PUBLISHED","title":"Junos OS: An unauthenticated adjacent attacker sending a malformed DHCP packet causes jdhcpd to crash","description":"A Buffer Access with Incorrect Length Value vulnerability in the jdhcpd daemon of Juniper Networks Junos OS, when DHCP snooping is enabled, allows an unauthenticated, adjacent, attacker to send a DHCP packet with a malformed DHCP option to cause jdhcp to crash creating a Denial of Service (DoS) condition.\n\nContinuous receipt of these DHCP packets using the malformed DHCP Option will create a sustained Denial of Service (DoS) condition.\n\n\nThis issue affects Junos OS:\n\n\n\n  *  from 23.1 before 23.2R2-S3,\n  *  from 23.4 before 23.4R2-S3,\n  *  from 24.2 before 24.2R2.\n\n\nThis issue isn't applicable to any versions of Junos OS before 23.1R1. \n\n\n\nThis issue doesn't affect vSRX Series which doesn't support DHCP Snooping. \n\nThis issue doesn't affect Junos OS Evolved.\n\nThere are no indicators of compromise for this issue.","publishedAt":"2025-04-09T19:46:55.976Z","updatedAt":"2025-04-28T16:21:26.535Z","severity":{"score":7.1,"label":"High","version":"4.0","vector":"CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:L/AU:Y/R:U/V:C/RE:M/U:Green","source":"juniper"},"assigner":"juniper","products":["Juniper Networks Junos OS"],"affected":[{"vendor":"Juniper Networks","product":"Junos OS","packageName":"jdhcpd","defaultStatus":"unaffected","versions":[{"version":"23.1","status":"affected","lessThan":"23.2R2-S3","versionType":"semver"},{"version":"23.4","status":"affected","lessThan":"23.4R2-S3","versionType":"semver"},{"version":"24.2","status":"affected","lessThan":"24.2R2","versionType":"semver"},{"version":"0","status":"unaffected","lessThanOrEqual":"23.1R1","versionType":"semver"}],"modules":["dhcp"]}],"references":["https://supportportal.juniper.net/JSA96448"],"weaknesses":["CWE-805"],"ingestedAt":"2026-10-29T20:08:39.238Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2025/21xxx/CVE-2025-21591.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.1","cveMetadata":{"cveId":"CVE-2025-21591","state":"PUBLISHED","datePublished":"2025-04-09T19:46:55.976Z","dateUpdated":"2025-04-28T16:21:26.535Z","assignerShortName":"juniper","assignerOrgId":"8cbe9d5a-a066-4c94-8978-4b15efeae968","dateReserved":"2024-12-26T14:47:11.667Z"},"containers":{"cna":{"title":"Junos OS: An unauthenticated adjacent attacker sending a malformed DHCP packet causes jdhcpd to crash","descriptions":[{"lang":"en","value":"A Buffer Access with Incorrect Length Value vulnerability in the jdhcpd daemon of Juniper Networks Junos OS, when DHCP snooping is enabled, allows an unauthenticated, adjacent, attacker to send a DHCP packet with a malformed DHCP option to cause jdhcp to crash creating a Denial of Service (DoS) condition.\n\nContinuous receipt of these DHCP packets using the malformed DHCP Option will create a sustained Denial of Service (DoS) condition.\n\n\nThis issue affects Junos OS:\n\n\n\n  *  from 23.1 before 23.2R2-S3,\n  *  from 23.4 before 23.4R2-S3,\n  *  from 24.2 before 24.2R2.\n\n\nThis issue isn't applicable to any versions of Junos OS before 23.1R1. \n\n\n\nThis issue doesn't affect vSRX Series which doesn't support DHCP Snooping. \n\nThis issue doesn't affect Junos OS Evolved.\n\nThere are no indicators of compromise for this issue."}],"affected":[{"vendor":"Juniper Networks","product":"Junos OS","packageName":"jdhcpd","defaultStatus":"unaffected","versions":[{"version":"23.1","status":"affected","lessThan":"23.2R2-S3","versionType":"semver"},{"version":"23.4","status":"affected","lessThan":"23.4R2-S3","versionType":"semver"},{"version":"24.2","status":"affected","lessThan":"24.2R2","versionType":"semver"},{"version":"0","status":"unaffected","lessThanOrEqual":"23.1R1","versionType":"semver"}],"modules":["dhcp"]}],"references":[{"url":"https://supportportal.juniper.net/JSA96448","tags":["vendor-advisory"]}],"metrics":[{"cvssV3_1":{"attackComplexity":"LOW","attackVector":"ADJACENT_NETWORK","availabilityImpact":"HIGH","baseScore":7.4,"baseSeverity":"HIGH","confidentialityImpact":"NONE","integrityImpact":"NONE","privilegesRequired":"NONE","scope":"CHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H","version":"3.1"},"format":"CVSS","scenarios":[{"lang":"en","value":"GENERAL"}]},{"cvssV4_0":{"Automatable":"YES","Recovery":"USER","Safety":"NOT_DEFINED","attackComplexity":"LOW","attackRequirements":"NONE","attackVector":"ADJACENT","baseScore":7.1,"baseSeverity":"HIGH","privilegesRequired":"NONE","providerUrgency":"GREEN","subAvailabilityImpact":"LOW","subConfidentialityImpact":"NONE","subIntegrityImpact":"NONE","userInteraction":"NONE","valueDensity":"CONCENTRATED","vectorString":"CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:L/AU:Y/R:U/V:C/RE:M/U:Green","version":"4.0","vulnAvailabilityImpact":"HIGH","vulnConfidentialityImpact":"NONE","vulnIntegrityImpact":"NONE","vulnerabilityResponseEffort":"MODERATE"},"format":"CVSS","scenarios":[{"lang":"en","value":"GENERAL"}]}],"problemTypes":[{"descriptions":[{"cweId":"CWE-805","description":"CWE-805: Buffer Access with Incorrect Length Value","lang":"en","type":"CWE"}]}],"providerMetadata":{"shortName":"juniper","orgId":"8cbe9d5a-a066-4c94-8978-4b15efeae968","dateUpdated":"2025-04-28T16:21:26.535Z"},"configurations":[{"lang":"en","supportingMedia":[{"base64":false,"type":"text/html","value":"The required minimal configuration is DHCP is configured with DHCP snooping enabled with&nbsp;<span style=\"background-color: var(--wht);\">the mine-dhcp-client-options and/or mine-dhcpv6-client-options.</span><p><span style=\"background-color: var(--wht);\">&nbsp; [ vlans &lt;vlan-name&gt; forwarding-options dhcp-security </span>mine-dhcp-client-options ]<br>&nbsp; [ mine-dhcpv6-client-options ]<br></p><p>Please note: It is atypical to use the above configuration with a DHCP server on the same device.</p>"}],"value":"The required minimal configuration is DHCP is configured with DHCP snooping enabled with the mine-dhcp-client-options and/or mine-dhcpv6-client-options.  [ vlans <vlan-name> forwarding-options dhcp-security mine-dhcp-client-options ]\n  [ mine-dhcpv6-client-options ]\n\n\nPlease note: It is atypical to use the above configuration with a DHCP server on the same device."}],"datePublic":"2025-04-09T16:00:00.000Z","exploits":[{"lang":"en","supportingMedia":[{"base64":false,"type":"text/html","value":"Juniper SIRT is not aware of any malicious exploitation of this vulnerability."}],"value":"Juniper SIRT is not aware of any malicious exploitation of this vulnerability."}],"solutions":[{"lang":"en","supportingMedia":[{"base64":false,"type":"text/html","value":"The following software releases have been updated to resolve this specific issue: 23.2R2-S3, 23.4R2-S3, 24.2R2, 24.4R1, and all subsequent releases.<br><br><br>"}],"value":"The following software releases have been updated to resolve this specific issue: 23.2R2-S3, 23.4R2-S3, 24.2R2, 24.4R1, and all subsequent releases."}],"source":{"advisory":"JSA96448","defect":["1827395"],"discovery":"INTERNAL"},"timeline":[{"lang":"en","time":"2025-04-09T16:00:00.000Z","value":"Initial Publication"}],"workarounds":[{"lang":"en","supportingMedia":[{"base64":false,"type":"text/html","value":"There are no known workarounds for this issue."}],"value":"There are no known workarounds for this issue."}],"x_generator":{"engine":"Vulnogram 0.1.0-dev"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2025-04-10T13:17:33.869610Z","id":"CVE-2025-21591","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2025-04-10T13:17:41.109Z"}}]}}}