{"id":"CVE-2023-49105","kind":"vulnerability","aliases":["CVE-2023-49105"],"related":[],"title":"owncloud server: An issue was discovered in ownCloud owncloud/core before 10.13.1","description":"ownCloud contains an improper authentication vulnerability that allows an attacker to access, modify, or delete any file without authentication if the username of a victim is known, and the victim has no signing-key configured.\n\nCISA required action: Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.","summary":"ownCloud has an authentication bypass where an attacker who knows a victim's username can read, change, or delete that user's files without logging in, if the victim has no signing key configured. CISA lists it as actively exploited.","severity":"critical","cvss":9.8,"epss":null,"exploited":true,"exploited_at":"2026-08-27T00:00:00+00:00","products":[{"name":"ownCloud ownCloud","fixed":[],"affected":"","ecosystem":"vendor"},{"name":"owncloud server","fixed":["10.13.1"],"affected":">= 10.6.0, < 10.13.1","ecosystem":"vendor"}],"ecosystems":["vendor"],"tags":["exploited","file-sharing","owncloud","self-hosted","vendor"],"not_affected_if":["managed-hosting","no-owncloud-deployment"],"how_to_check":"Check whether the ownCloud app's signing-key is configured for users (look for signing-key settings in your ownCloud admin config) unknown\nConfirm your ownCloud version against the vendor advisory: unknown\nReview web server logs for unauthenticated requests to file endpoints: unknown","fix":"Apply the vendor's fixed ownCloud release or mitigation; the sources do not name the fixed version. Configure a signing key for affected users as the interim mitigation, or take the service offline if no mitigation is available.","status":"open","published_at":"2023-11-21T22:15:08+00:00","first_seen_at":"2026-10-23T19:11:51+00:00","triaged_at":"2026-10-23T20:31:47+00:00","updated_at":"2026-10-23T23:44:52+00:00","category":"vendor","confidence":0.7,"triage":{"at":"2026-10-23T20:31:47Z","model":"claude-haiku-5-5","output":{"fix":"Apply the vendor's fixed ownCloud release or mitigation; the sources do not name the fixed version. Configure a signing key for affected users as the interim mitigation, or take the service offline if no mitigation is available.","summary":"ownCloud has an authentication bypass where an attacker who knows a victim's username can read, change, or delete that user's files without logging in, if the victim has no signing key configured. CISA lists it as actively exploited.","category":"vendor","who_cares":["owncloud","self-hosted","file-sharing"],"confidence":0.7,"analyst_note":"Get the fixed version and the vendor signing-key mitigation steps from the ownCloud advisory for CVE-2023-49105 and the CISA KEV entry.","how_to_check":"Check whether the ownCloud app's signing-key is configured for users (look for signing-key settings in your ownCloud admin config) unknown\nConfirm your ownCloud version against the vendor advisory: unknown\nReview web server logs for unauthenticated requests to file endpoints: unknown","needs_analyst":true,"not_affected_if":["managed-hosting","no-ownCloud-deployment"],"severity_if_unknown":"critical"},"cost_usd":0.000426,"input_tokens":2202,"output_tokens":411,"severity_before":"unknown"},"analyst_status":null,"analyst_note":null,"search":"'-04':124C,150C,181C '-2023':13A,16A '-49105':14A,17A '10.13.1':11A '26':123C,149C,180C 'access':82C 'accord':113C 'action':109C 'activ':69B 'adher':177C 'allow':78C 'appli':110C 'applic':147C 'asset':171C 'attack':38B,80C 'authent':34B,75C,89C 'base':128C 'bod':122C,148C,179C 'bypass':35B 'chang':47B 'cisa':65B,107C,120C,137C 'cloud':153C 'complianc':118C 'configur':64B,106C 'contain':72C 'cve':12A,15A 'delet':49B,85C 'discontinu':156C 'discov':6A 'ensur':117C,176C 'evalu':169C 'exploit':22B,70B 'exposur':174C 'file':24B,53B,87C 'file-shar':23B 'follow':146C 'forens':139C 'guidanc':135C,151C 'guidelin':183C 'host':29B 'improp':74C 'instruct':116C 'internet':173C 'issu':4A 'key':63B,105C 'know':40B 'known':97C 'list':66B 'log':55B 'mitig':111C,162C 'modifi':83C 'note':134C,145C 'owncloud':1A,8A,18A,19A,20A,26B,31B,71C 'owncloud/core':9A 'patch':182C 'priorit':125C 'product':160C 'read':46B 'requir':108C,141C 'respons':167C 'risk':130C 'secur':126C 'see':131C,142C 'self':28B 'self-host':27B 'server':2A,21A 'servic':154C 'share':25B 'sign':62B,104C 'signing-key':103C 'stakehold':165C 'triag':140C 'unavail':164C 'updat':127C 'url':132C,143C 'use':157C 'user':51B 'usernam':44B,92C 'vendor':30B,115C 'victim':42B,59B,95C,100C 'vulner':76C 'without':54B,88C","nicknames":[],"mitigations":[],"who_affected":null,"tier":null,"verified":{},"analyst_revisit_at":null,"first_public_at":"2023-11-21T22:15:08+00:00","kev":{"dateAdded":"2026-08-27","dueDate":"2026-08-30","requiredAction":"Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.","knownRansomwareCampaignUse":"Unknown"},"cvss_vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","cvss_by":"cve@mitre.org","poc_count":0,"sources":[{"source":"kev","external_id":"CVE-2023-49105","url":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog?search_api_fulltext=CVE-2023-49105","severity":null,"published_at":"2026-08-27T00:00:00+00:00","modified_at":null,"first_seen_at":"2026-10-23T19:11:51+00:00","fetched_at":"2026-10-25T14:39:37+00:00","note":null},{"source":"nvd","external_id":"CVE-2023-49105","url":"https://nvd.nist.gov/vuln/detail/CVE-2023-49105","severity":null,"published_at":"2023-11-21T22:15:08+00:00","modified_at":"2026-08-28T12:21:09+00:00","first_seen_at":"2026-10-23T23:44:52+00:00","fetched_at":"2026-10-23T23:44:52+00:00","note":null}],"documents":[],"notice":"Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai"}