Ubiquiti UniFi Devices Use of AES-CBC Allows Key Recovery and Unauthorized Device Control
Ubiquiti UniFi Network Controller prior to 5.10.12 (excluding 5.6.42), UAP FW prior to 4.0.6, UAP-AC, UAP-AC v2, and UAP-AC Outdoor FW prior to 3.8.17, USW FW prior to 4.0.6, USG FW prior to 4.4.34 uses AES-CBC encryption for device-to-controller communication, which contains cryptographic weaknesses that allow attackers to recover encryption keys from captured traffic. Attackers with adjacent network access can capture sufficient encrypted traffic and exploit AES-CBC mode vulnerabilities to derive the encryption keys, enabling unauthorized control and management of network devices.
- Published
- Mar 27, 2026
- Updated
- Jul 15, 2026
- EPSS
- 0.1% · 0th percentile
- CWE
- CWE-327
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Report tools
Action score
36
Monitor
Low priority for now.
- CVSS
- 36 / 40 · 9.0 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 0 / 30 · 0.1%
CISA SSVC decision
- Exploitation
- none
- Automatable
- no
- Technical impact
- total
Vulnrichment: CISA's decision-tree inputs.
CNA vs NVD score
- NVD
- —
- CNA · VulnCheck
- 9.0
- NVD has not scored this yet; the score shown is the CNA’s.
CVSS:4.0/AV:A/AC:H/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H
The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.
Noroxi analysis
No Noroxi analysis for this record yet
We don't hand-write analysis for the hundreds of thousands of vulnerabilities in the database; that wouldn't be honest. For notable, high-impact vulnerabilities our team writes the mechanism, detection and remediation steps.
We use this product, ask for helpAffected systems
—
Versions reported by the vendor
Affected version ranges reported by the assigning authority (VulnCheck). Independent of NVD's CPE analysis and usually ahead of it.
Ubiquiti UniFi Network Controller
- before 5.6.42affected · semver
- 5.6.43 and later · before 5.10.12affected · semver
Ubiquiti UniFi UAP Firmware
- before 4.0.6affected · semver
Ubiquiti UniFi UAP-AC Firmware
- before 3.8.17affected · semver
Ubiquiti UniFi USG Firmware
- before 4.4.34affected · semver
Ubiquiti UniFi USW Firmware
- before 4.0.6affected · semver
Same product
ubiquiti: all recordsOther highest-scoring records for the same primary product.
- CVE-2019-25652UniFi Network Controller Improper Certificate Validation Leading to Credential Theft via MITM30Monitor
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
| Product / package | Fixed version | Source |
|---|---|---|
| Ubiquiti UniFi Network Controller | 5.10.12 | Vendor (CNA) |
| Ubiquiti UniFi Network Controller | 5.6.42 | Vendor (CNA) |
| Ubiquiti UniFi UAP Firmware | 4.0.6 | Vendor (CNA) |
| Ubiquiti UniFi UAP-AC Firmware | 3.8.17 | Vendor (CNA) |
| Ubiquiti UniFi USG Firmware | 4.4.34 | Vendor (CNA) |
| Ubiquiti UniFi USW Firmware | 4.0.6 | Vendor (CNA) |
Exploit status
No known public exploit
No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.
Research context
For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.
Timeline
From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.
No dated events beyond publication.
FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).
Patch and commit links
Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.
No commit or PR link among the references.
Credits
All researchersFinders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.
No credits in the CNA record.
Variant candidates
Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.
No nightly-computed relations.
Chain candidates
An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.
—
Bug bounty scope
The product’s vendor appears in a public program. Matched by name; verify the scope text in the program.
Technical details
Attack conditions
- Someone on the same network segment can trigger it.
- No account or password is required.
- No user action is required.
- Special conditions such as timing or configuration are required.
If successful
- Confidentiality
- Integrity
- Availability
- Attack vector
- Adjacent
- Attack complexity
- High
- Privileges required
- None
- User interaction
- None
- Scope
- X
Weakness class (CWE)
CWE-327 · Use of a Broken or Risky Cryptographic AlgorithmCVSS vector
CVSS:4.0/AV:A/AC:H/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/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
nvd-secondary
Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
Attack patterns (CAPEC)
- Encryption Brute ForcingCAPEC-20likelihood: Low · Low
- Creating a Rogue Certification Authority CertificateCAPEC-459likelihood: Medium · Very High
- Signature SpoofCAPEC-473
- Signature Spoofing by Improper ValidationCAPEC-475likelihood: Low · High
- Cryptanalysis of Cellular EncryptionCAPEC-608High
- Rooting SIM CardsCAPEC-614High
- CryptanalysisCAPEC-97likelihood: Low · Very High
Change log
- Fix✗ → ✓
For records you follow, these changes also arrive as notifications. →
References
- community.ui.com/releases/Security-Advisory-Bulletin-004-004/462e561b-9efd-4c23-bfa7-53d59cc64ecb
- www.vulncheck.com/advisories/ubiquiti-unifi-devices-use-of-aes-cbc-allows-key-recovery-and-unauthorized-device-control
Vendor advisories and official records. Exploit/PoC links are deliberately left out.