Arbitrary file write via unsanitized upload filename
Published Jun 19, 2025 · Updated Jun 23, 2025
Path traversal in Upsonic before 0.56.0 allows remote attackers to write uploaded files outside the intended temporary directory. The /markdown/upload handler in markdown/server.py passes the untrusted file.filename value directly to os.path.join and opens the resulting path for writing without validating its resolved location. A multipart filename containing parent-directory segments is sufficient to create or overwrite files writable by the service account; no file-read capability is demonstrated.
Summary
What happened
Path traversal in Upsonic before 0.56.0 allows remote attackers to write uploaded files outside the intended temporary directory. The /markdown/upload handler in markdown/server.py passes the untrusted file.filename value directly to os.path.join and opens the resulting path for writing without validating its resolved location. A multipart filename containing parent-directory segments is sufficient to create or overwrite files writable by the service account; no file-read capability is demonstrated.
The record
- CVE
- CVE-2025-6278
- Published
- Jun 19, 2025
- Updated
- Jun 23, 2025
- Vendor
- Upsonic
- Product
- Upsonic
- Classifications
- CWE-22, CAPEC-126, T1190
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Jun 19, 2025CVE publishedPublication date reported by the CVE source.
- Jun 23, 2025Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
Compare your product and version with the public record. A matching version still requires validation against your environment.
Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=0.55.0
- Affected versionversion=0.55.1
- Affected versionversion=0.55.2
- Affected versionversion=0.55.3
- Affected versionversion=0.55.4
- Affected versionversion=0.55.5
- Affected versionversion=0.55.6
What conditions does exploitation require?
What is affected?
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- GitHub issue 356 proof of conceptproof of concept · demonstrated
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
See the directory against your own environment.
Your stack
Check the software in your environment
Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.
Book a demo