RustDesk versions before 1.4.7 contain an uncontrolled speculative memory allocation vulnerability in BytesCodec. Before authentication, the decoder trusts the payload length encoded in a four-byte frame header and reserves that amount before receiving the payload. A crafted header can request up to 1,073,741,823 bytes of capacity, allowing unauthenticated attackers to use concurrent TCP connections to cause memory exhaustion and denial of service.
The fix caps header-triggered speculative preallocation at 256 KiB.
Attack Parameters
Attack Vector
Network
Can be exploited remotely
Attack Complexity
Low
Easy to exploit
Attack Requirements
None
No additional conditions
Privileges Required
None
No privileges needed
User Interaction
None
No user interaction needed
Impact Assessment
Confidentiality
None
No data leak
Integrity
None
No data modification
Availability
High
Complete denial of service
CVSS Vector v4.0
Weakness Type (CWE)
References 4
https://github.com/rustdesk/hbb_common/commit/547da54b4ee58eed47163fbd47edb4639…
disclosure@vulncheck.com
https://github.com/rustdesk/rustdesk/commit/518296f2570d107ad416f29ade5fcce3177…
disclosure@vulncheck.com
https://github.com/rustdesk/rustdesk/releases/tag/1.4.7
disclosure@vulncheck.com
https://www.vulncheck.com/advisories/rustdesk-uncontrolled-memory-allocation-do…
disclosure@vulncheck.com