HBS 3 Hybrid Backup Sync: Use of Hard-coded Cryptographic Key
CVE-2025-62841 is a high-severity use of hard-coded cryptographic key vulnerability in HBS 3 Hybrid Backup Sync from QNAP, with a CVSS 4.0 base score of 8.7 out of 10. It can be exploited from the same local network by an unauthenticated attacker, without any action from a user. The record lists version 26.4.0.521 as the first without the flaw, so updating HBS 3 Hybrid Backup Sync to that release or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.24% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update HBS 3 Hybrid Backup Sync to 26.4.0.521 or a later version.
- Update Hybrid Backup Sync to 26.4.0.521 or 26.4.1.563, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| QNAP | HBS 3 Hybrid Backup Sync | 26.4.x up to, but not including, 26.4.0.521 | 26.4.0.521 |
| QNAP | Hybrid Backup Sync | 26.4.x up to, but not including, 26.4.0.521; 26.4.x up to, but not including, 26.4.1.563 | 26.4.0.521, 26.4.1.563 |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- AdjacentThe attacker must be on the same local network segment.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Attack requirements
- NoneThe attack does not depend on a particular deployment or configuration.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Confidentiality (vulnerable system)
- HighSerious loss of confidentiality on the vulnerable system.
- Integrity (vulnerable system)
- HighSerious loss of integrity on the vulnerable system.
- Availability (vulnerable system)
- HighSerious loss of availability on the vulnerable system.
- Confidentiality (other systems)
- NoneNo loss of confidentiality on systems beyond the vulnerable one.
- Integrity (other systems)
- NoneNo loss of integrity on systems beyond the vulnerable one.
- Availability (other systems)
- NoneNo loss of availability on systems beyond the vulnerable one.
Vector: CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/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. Scored by CNA (qnapsecurity.com.tw).
Official description
An use of hard-coded cryptographic key vulnerability has been reported to affect HBS 3 Hybrid Backup Sync and Hybrid Backup Sync. If exploited, the vulnerability could allow remote attackers to compromise the security of the system. We have already fixed the vulnerability in the following version: HBS 3 Hybrid Backup Sync 26.4.0.521 and later Hybrid Backup Sync 26.4.0.521 and later Hybrid Backup Sync 26.4.1.563 and later
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Use of Hard-coded Cryptographic Key
The product uses a hard-coded, unchangeable cryptographic key.
How developers prevent this class of flaw
- Prevention schemes mirror that of hard-coded password storage.
More Use of Hard-coded Cryptographic Key vulnerabilities (CWE-321)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
Our coverage
Other vulnerabilities in HBS 3 Hybrid Backup Sync
- 8.7 High severity
- 7.8 High severity
- 9.1 Critical severity
- 9.8 Critical severity
Recent Use of Hard-coded Cryptographic Key vulnerabilities
- 9.8 Critical severity
- 9.8 Critical severity
- 7.7 High severity
- 8.1 High severity
- 8.5 High severity
- 8.1 High severity
Spotted an error? Tell us.