Loading vulnerability…
CVE-2021-28799 is an improper authorization vulnerability in QNAP Hybrid Backup Sync 3 (HBS 3) on QNAP NAS devices. The flaw affects HBS 3 versions prior to v16.0.0415 on QTS 4.5.2, prior to v3.0.210412 on QTS 4.3.6, prior to v3.0.210411 on QTS 4.3.4 and QTS 4.3.3, prior to v16.0.0419 on QuTS hero h4.5.1, and prior to v16.0.0419 on QuTScloud c4.5.1 through c4.5.4. Successful exploitation allows a remote attacker to authenticate to the device without proper authorization. Reporting associated with in-the-wild exploitation indicates the weakness was used to bypass authentication in HBS 3 and then execute commands on affected NAS systems, making the issue operationally equivalent to remote unauthorized access with command execution on exposed devices. HBS 2 and HBS 1.3 are not affected.
Mallory correlates every CVE against your assets, your vendors, and active adversary campaigns. Know which vulnerabilities matter for you, not just which ones are loud.
What it means. What to do now. Patch path, mitigations, and the assume-compromise checklist.
What an attacker gets, and what they’ve been doing with it.
If you can’t patch tonight, do this now.
Patch, then assume compromise.
No public exploits tracked yet. Mallory keeps watching.
No public exploit code observed for this vulnerability.
Products and vendors Mallory has correlated with this vulnerability. Open in Mallory to drill down to specific CPE configurations and version ranges.
Vendor-confirmed product mapping. Mallory continuously reconciles this list against your asset inventory.
10 sources tracked across advisories, community write-ups, and news. New activity surfaces here as Mallory finds it.
An improper authorization vulnerability in QNAP HBS 3 (Hybrid Backup Sync) allows remote attackers to log in to affected NAS devices.
A remote code execution vulnerability affecting QNAP NAS devices, mentioned as a possible initial access vector used to compromise the FTP server that hosted SockDetour.
A remote code execution vulnerability referenced as the likely flaw used to compromise a QNAP NAS delivery server previously infected with QLocker ransomware.
An improper authorization vulnerability in QNAP Hybrid Backup Sync (HBS 3) that allows remote attackers to log in to affected devices and has been used to deliver ransomware to QNAP NAS systems.
Query your assets running an affected version, and investigate the blast radius.
Every observed campaign linking this CVE to a named adversary.
Malware families riding this exploit, with evidence and IOCs.
YARA, Sigma, Snort, and vendor rules, auto-deployed to your SIEM.
Cross-references every affected SKU, including bundled OEM variants.
Community discussion across Reddit, Mastodon, and other social sources.