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TI-2023-12582 Aliases CVE-2023-27992GHSA-5wv9-h9hr-4p52

OS command injection in Zyxel NAS326 firmware

Priority CRITICAL 100Exploited in the wildCWE-78Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Impact type
Code execution
Confidentiality · integrity · availability
High · High · High
Fix status
Fixed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA. Impact type from CWE-78.

Summary

The pre-authentication command injection vulnerability in the Zyxel NAS326 firmware versions prior to V5.21(AAZF.14)C0, NAS540 firmware versions prior to V5.21(AATB.11)C0, and NAS542 firmware versions prior to V5.21(ABAG.11)C0 could allow an unauthenticated attacker to execute some operating system (OS) commands remotely by sending a crafted HTTP request.

Why it matters now

Exploitation Active In CISA KEV since 2023-06-23CISA due date 2023-07-14
EPSS 0.82264 99th percentileScored 2026-11-07
Fix Fixed NAS326 firmware (Zyxel): V5.21(AAZF.14)C0NAS540 firmware (Zyxel): V5.21(AATB.11)C0+1 more product

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
Active
Automatable
Yes
Technical impact
Total

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
ZyxelNAS326 firmwarebefore V5.21(AAZF.14)C0V5.21(AAZF.14)C0Patch availableCNA
ZyxelNAS540 firmwarebefore V5.21(AATB.11)C0V5.21(AATB.11)C0Patch availableCNA
ZyxelNAS542 firmwarebefore V5.21(ABAG.11)C0V5.21(ABAG.11)C0Patch availableCNA
  • NAS326 firmware VendorZyxel Affected before V5.21(AAZF.14)C0 Fixed in V5.21(AAZF.14)C0 Patch available CNA
  • NAS540 firmware VendorZyxel Affected before V5.21(AATB.11)C0 Fixed in V5.21(AATB.11)C0 Patch available CNA
  • NAS542 firmware VendorZyxel Affected before V5.21(ABAG.11)C0 Fixed in V5.21(ABAG.11)C0 Patch available CNA

CPE configurations NVD · 6

CPEVersionsRoleVendor
cpe:2.3:o:zyxel:nas326_firmware:*:*:*:*:*:*:*:*before 5.21\(aazf.14\)c0VulnerableZyxel
cpe:2.3:h:zyxel:nas326:-:*:*:*:*:*:*:*not specified by NVDRunning onZyxel
cpe:2.3:o:zyxel:nas540_firmware:*:*:*:*:*:*:*:*before 5.21\(aatb.11\)c0VulnerableZyxel
cpe:2.3:h:zyxel:nas540:-:*:*:*:*:*:*:*not specified by NVDRunning onZyxel
cpe:2.3:o:zyxel:nas542_firmware:*:*:*:*:*:*:*:*before 5.21\(abag.11\)c0VulnerableZyxel
cpe:2.3:h:zyxel:nas542:-:*:*:*:*:*:*:*not specified by NVDRunning onZyxel
  • cpe:2.3:o:zyxel:nas326_firmware:*:*:*:*:*:*:*:* Versions before 5.21\(aazf.14\)c0 Vulnerable ·Zyxel
  • cpe:2.3:h:zyxel:nas326:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Zyxel
  • cpe:2.3:o:zyxel:nas540_firmware:*:*:*:*:*:*:*:* Versions before 5.21\(aatb.11\)c0 Vulnerable ·Zyxel
  • cpe:2.3:h:zyxel:nas540:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Zyxel
  • cpe:2.3:o:zyxel:nas542_firmware:*:*:*:*:*:*:*:* Versions before 5.21\(abag.11\)c0 Vulnerable ·Zyxel
  • cpe:2.3:h:zyxel:nas542:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Zyxel

Remediation

  • Fix · CNA NAS326 firmware (Zyxel) Fixed in V5.21(AAZF.14)C0
  • Fix · CNA NAS540 firmware (Zyxel) Fixed in V5.21(AATB.11)C0
  • Fix · CNA NAS542 firmware (Zyxel) Fixed in V5.21(ABAG.11)C0

Timeline

  1. 2023-06-23 Added to CISA KEV
  2. 2026-10-02 Threatist record created from CVE-2023-27992
  3. 2026-10-03 Alias added: GHSA-5wv9-h9hr-4p52

References

Patch 1

  • TI-2020-07267 OS command injection in Zyxel NAS326 KEVCVSS 3.1CRITICAL 9.8
  • TI-2024-19735 OS command injection in Zyxel NAS326 firmware CVSS 3.1CRITICAL 9.8
  • TI-2024-19736 OS command injection in Zyxel NAS326 firmware CVSS 3.1CRITICAL 9.8
  • TI-2023-04130 OS command injection in Zyxel NAS326 firmware CVSS 3.1CRITICAL 9.8
  • TI-2023-04129 OS command injection in Zyxel NAS326 firmware CVSS 3.1CRITICAL 9.8
  • TI-2023-19361 OS command injection in Zyxel NAS326 firmware CVSS 3.1HIGH 8.8
See all 23 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences