RustDesk Client Transmits Preset Address Book Password Verbatim in Heartbeat Sync

Summary

CVE	CVE-2026-30796
State	PUBLISHED
Assigner	VULSec
Source Priority	CVE Program / NVD first with legacy fallback
Published	2026-03-05 16:16:21 UTC
Updated	2026-06-22 14:17:35 UTC
Description	Cleartext Transmission of Sensitive Information, Insufficiently Protected Credentials vulnerability in rustdesk-client RustDesk Client rustdesk-client on Windows, MacOS, Linux, iOS, Android (Address book sync, Heartbeat sync loop modules) allows Sniffing Attacks. The client places the preset address-book password verbatim into the heartbeat sync JSON body (src/hbbs_http/sync.rs). Over an intact HTTPS session it is not exposed in transit, but it is a reusable shared secret rather than a zero-knowledge proof, so it is recovered by any party that becomes the API endpoint - under the automatic invalid-certificate TLS downgrade (CVE-2026-30794) or a re-homed/rogue API server (CVE-2026-30797) - and the leaked credential then authorizes the server-side address book. This vulnerability is associated with program files src/hbbs_http/sync.rs and program routines heartbeat sync body builder (emits preset-address-book-password). This issue affects RustDesk Client: through 1.4.8.

Risk And Classification

Primary CVSS: v4.0 6.9 MEDIUM from 2fdefc65-d750-4b8d-96ee-6e2c0c42dbfe

CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:N/SC:H/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Problem Types: CWE-522 | CWE-522 CWE-522 Insufficiently Protected Credentials

Version	Source	Type	Score	Severity	Vector
4.0	2fdefc65-d750-4b8d-96ee-6e2c0c42dbfe	Secondary	6.9	MEDIUM	`CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:N/SC:H/SI:N/SA:N/E:X/C...`
4.0	CNA	CVSS	6.9	MEDIUM	`CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:N/SC:H/SI:N/SA:N`
3.1	[email protected]	Primary	7.5	HIGH	`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N`

CVSS v4.0 Breakdown

Attack Vector

Network

Attack Complexity

Low

Attack Requirements

Present

Privileges Required

None

User Interaction

None

Confidentiality

None

Integrity

None

Availability

None

Sub Conf.

High

Sub Integrity

None

Sub Availability

None

CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:N/SC:H/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

CVSS v3.1 Breakdown

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

None

Availability

None

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

NVD Known Affected Configurations (CPE 2.3)

Type	Vendor	Product	Version	Update	Edition	Language
Operating System	Apple	Macos	-	All	All	All
Operating System	Linux	Linux Kernel	-	All	All	All
Operating System	Microsoft	Windows	-	All	All	All
Application	Rustdesk	Rustdesk Server	All	All	All	All

Vendor Declared Affected Products

Source	Vendor	Product	Version	Platforms
CNA	Rustdesk-client	RustDesk Client	affected 1.4.8 custom	Windows, MacOS, Linux, iOS, Android

References

Reference	Source	Link	Tags
docs.google.com/document/d/e/2PACX-1vSds6jjpd38oO_yIAyd1HYtKNUuea-I-ozAPpGhYI...	2fdefc65-d750-4b8d-96ee-6e2c0c42dbfe	docs.google.com	Exploit, Third Party Advisory
www.vulsec.org	2fdefc65-d750-4b8d-96ee-6e2c0c42dbfe	www.vulsec.org	Not Applicable
rustdesk.com/docs/en	2fdefc65-d750-4b8d-96ee-6e2c0c42dbfe	rustdesk.com	Product, Vendor Advisory
CVE Program record	CVE.ORG	www.cve.org	canonical
NVD vulnerability detail	NVD	nvd.nist.gov	canonical, analysis

Vendor Comments And Credit

Discovery Credit

CNA: Erez Kalman (en)

Additional Advisory Data

Solutions

CNA: Transition Address Book API to SRP (Secure Remote Password)

Workarounds

CNA: Avoid setting address book passwords; use account-based access only

Exploits

CNA: PoC available. Trivially exploitable.

There are currently no legacy QID mappings associated with this CVE.