Client crash via unchecked RFX quantization indices
Published Aug 31, 2023 · Updated Nov 3, 2025
Out-of-bounds read in FreeRDP before 2.11.0 and 3.0.0-beta1 through 3.0.0-beta2 allows remote attackers to crash RDP clients. The RFX tileset parser reads quantIdxY, quantIdxCb, and quantIdxCr without checking each index against numQuant before quantization decoding. A malicious or compromised RDP server must send crafted RemoteFX tile data to a FreeRDP-based client; the data-passthrough proxy is not affected.
Summary
What happened
Out-of-bounds read in FreeRDP before 2.11.0 and 3.0.0-beta1 through 3.0.0-beta2 allows remote attackers to crash RDP clients. The RFX tileset parser reads quantIdxY, quantIdxCb, and quantIdxCr without checking each index against numQuant before quantization decoding. A malicious or compromised RDP server must send crafted RemoteFX tile data to a FreeRDP-based client; the data-passthrough proxy is not affected.
The record
- CVE
- CVE-2023-39353
- Published
- Aug 31, 2023
- Updated
- Nov 3, 2025
- Vendor
- FreeRDP
- Product
- FreeRDP
- Classifications
- T1499.004
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Aug 31, 2023CVE publishedPublication date reported by the CVE source.
- Nov 3, 2025Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=< 2.11.0
- Affected versionversion=>= 3.0.0-beta1, < 3.0.0-beta3
What conditions does exploitation require?
What is affected?
Published CVSS scores
No CVSS assessment is available in this record.
CVSS describes severity. EPSS estimates exploitation probability.
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
- Upstream crafted RFX quantization-index proof of conceptproof of concept · demonstrated
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Technologies
Your stack
See the directory against your own environment.
Your stack
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