Capgo Build Upload Proxy Authorization Bypass via TUS Resource
- Published
- Last modified
- Where the record stands: published, rejected by its publisher, or superseded by another id.What do these mean? →
- published
- Whether CISA lists it in its Known Exploited Vulnerabilities catalog: proof that attackers are using it.What do these mean? →
- Not listed in CISA KEV
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
- Exploitation: poc
- Automatable: no
- Technical impact: partial
Summary
Capgo (capgo.app) exposes a native build TUS upload proxy (supabase/functions/_backend/public/build/upload.ts) that authorizes a caller against a single build job identified by the supplied builder_job_id and validates only that job's stored upload_path, but then forwards the user-controlled TUS resource suffix taken from /build/upload/:jobId/* to the builder service while injecting Capgo's privileged builder API key. Because the forwarded suffix is never bound to the authorized job's upload_path or upload_session_key, a caller holding a valid 'all' or 'write' Capgo API key with app.build_native permission for one application can use its authorized proxy path for job A to write to the TUS upload resource of another job B, provided that resource suffix is known or exposed, corrupting that build's artifacts. All versions are affected; no patch was available at the time of advisory publication.
Timeline
- CVE published
- CISA SSVC assessment
Exploitation: poc · Automatable: no · Technical impact: partial
- Record last updated
Affected versions
- Cap-go capgo.app
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