MISP contains a mass assignment vulnerability in the event delegation feature. When a user with delegation permission submits a delegation request, the application authorized the user against the event identified in the URL but then persisted the entire submitted record, including caller-supplied fields such as the primary key and event_id.
An authenticated attacker could inject a primary key or event_id into the delegation payload to retarget an existing delegation record to any event on the instance. Because a delegation row grants the requesting organisation read access to the event it references, this effectively granted read access to arbitrary events belonging to other organisations. If the target organisation subsequently accepted the delegation, ownership of the event was transferred and the original record was deleted.
Preconditions:
- An authenticated user with the delegation permission (perm_delegate)
- The MISP.delegation server setting must be enabled
Impact:
- Confidentiality: read access to any event on the instance
- Integrity: overwriting existing delegation records and transferring event ownership
Affected versions: MISP < 2.5.48
"}],"value":"MISP contains a mass assignment vulnerability in the event delegation feature. When a user with delegation permission submits a delegation request, the application authorized the user against the event identified in the URL but then persisted the entire submitted record, including caller-supplied fields such as the primary key and event_id.\n\nAn authenticated attacker could inject a primary key or event_id into the delegation payload to retarget an existing delegation record to any event on the instance. Because a delegation row grants the requesting organisation read access to the event it references, this effectively granted read access to arbitrary events belonging to other organisations. If the target organisation subsequently accepted the delegation, ownership of the event was transferred and the original record was deleted.\n\nPreconditions:\n\n- An authenticated user with the delegation permission (perm_delegate)\n\n- The MISP.delegation server setting must be enabled\n\nImpact:\n\n- Confidentiality: read access to any event on the instance\n\n- Integrity: overwriting existing delegation records and transferring event ownership\n\nAffected versions: MISP < 2.5.48"}],"impacts":[{"capecId":"CAPEC-12","descriptions":[{"lang":"en","value":"CAPEC-12 Mass Assignment"}]}],"metrics":[{"cvssV4_0":{"Automatable":"NOT_DEFINED","Recovery":"NOT_DEFINED","Safety":"NOT_DEFINED","attackComplexity":"LOW","attackRequirements":"NONE","attackVector":"NETWORK","baseScore":8.7,"baseSeverity":"HIGH","privilegesRequired":"LOW","providerUrgency":"NOT_DEFINED","subAvailabilityImpact":"NONE","subConfidentialityImpact":"NONE","subIntegrityImpact":"NONE","userInteraction":"NONE","valueDensity":"NOT_DEFINED","vectorString":"CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:L/SC:N/SI:N/SA:N","version":"4.0","vulnAvailabilityImpact":"LOW","vulnConfidentialityImpact":"HIGH","vulnIntegrityImpact":"HIGH","vulnerabilityResponseEffort":"NOT_DEFINED"},"format":"CVSS","scenarios":[{"lang":"en","value":"GENERAL"}]}],"problemTypes":[{"descriptions":[{"cweId":"CWE-915","description":"CWE-915 Improperly Controlled Modification of Dynamically-Determined Object Attributes","lang":"en","type":"CWE"}]},{"descriptions":[{"cweId":"CWE-639","description":"CWE-639 Authorization Bypass Through User-Controlled Key","lang":"en","type":"CWE"}]}],"providerMetadata":{"dateUpdated":"2026-09-30T09:12:56.533Z","orgId":"5a6e4751-2f3f-4070-9419-94fb35b644e8","shortName":"CIRCL"},"references":[{"name":"Security patch","tags":["patch"],"url":"https://github.com/MISP/MISP/commit/d1f5684f9"}],"solutions":[{"lang":"en","supportingMedia":[{"base64":false,"type":"text/html","value":"The delegation record is now constructed from a strict allow-list of fields rather than persisting the raw user-submitted payload. The event_id is always derived from the authorized event in the URL, the requester_org_id is always taken from the authenticated session, and the primary key is never included in the saved data. Only message, distribution, and sharing_group_id are accepted from user input, eliminating the ability to retarget or overwrite existing delegation records.
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Human validation is required before publication.","gna_source":1,"models":[{"gna_source":1,"identifier":"qwen3.8:27b","name":"qwen3.8:27b","source":"ollama"}],"review_status":"full","scope":"record","tags":["ai-computer-assisted:llm-generated","ai-computer-assisted:classification"]}]},"bcp-05-x-02":{"x_patch2vuln":{"assumptions":["The affected version boundary (< 2.5.48) is inferred from the tag_version_boundary metadata showing v2.5.48 as the nearest tag with 22 commits after the fix; the exact last affected release is not explicitly stated in the patch.","PR:L assumes the attacker needs only the perm_delegate permission, which is a non-admin role; the exact role configuration may vary by deployment.","VA:N assumes the availability impact (deletion of the original event) requires victim acceptance and is therefore not a direct availability impact of the vulnerability itself.","The CAPEC-12 mapping is the closest standard pattern; the vulnerability also has IDOR characteristics (CWE-639) but CAPEC-12 best captures the mass-assignment mechanism demonstrated in the patch.","The MISP.delegation server setting must be enabled for the vulnerability to be exploitable; this is a deployment configuration assumption."],"capecRationale":[{"capecId":"CAPEC-12","rationale":"The attacker manipulates hidden or additional fields in a form/API request (injecting id and event_id into the EventDelegation payload) to modify data beyond what the application intended to accept. 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When a user with delegation permission submits a delegation request, the application authorized the user against the event identified in the URL but then persisted the entire submitted record, including caller-supplied fields such as the primary key and event_id.\n\nAn authenticated attacker could inject a primary key or event_id into the delegation payload to retarget an existing delegation record to any event on the instance. Because a delegation row grants the requesting organisation read access to the event it references, this effectively granted read access to arbitrary events belonging to other organisations. If the target organisation subsequently accepted the delegation, ownership of the event was transferred and the original record was deleted.\n\nPreconditions:\n\n- An authenticated user with the delegation permission (perm_delegate)\n\n- The MISP.delegation server setting must be enabled\n\nImpact:\n\n- Confidentiality: read access to any event on the instance\n\n- Integrity: overwriting existing delegation records and transferring event ownership\n\nAffected versions: MISP < 2.5.48","Type":"Description","Title":"MISP Event Delegation Mass Assignment Allows Retargeting Delegat"}]}}}