What’s Vulnerable › Vulnerabilities

CVE-2021-35032

• Severity: high (CVSS 7.8 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.2% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2021-12-28 · updated 2026-06-17
• Weakness: CWE-78

Description

A vulnerability in the 'libsal.so' of the Zyxel GS1900 series firmware version 2.60 could allow an authenticated local user to execute arbitrary OS commands via a crafted function call.

Affected products

• Zyxel GS1900-10HP firmware: before 2.70\(aazi.0\)-20211208 — fixed in 2.70\(aazi.0\)-20211208
• Zyxel GS1900-16 firmware: before 2.70\(aahj.0\)-20211208 — fixed in 2.70\(aahj.0\)-20211208
• Zyxel GS1900-24 firmware: before 2.70\(aahl.0\)-20211208 — fixed in 2.70\(aahl.0\)-20211208
• Zyxel GS1900-24E firmware: before 2.70\(aahk.0\)-20211208 — fixed in 2.70\(aahk.0\)-20211208
• Zyxel GS1900-24EP firmware: before 2.70\(abto.0\)-20211208 — fixed in 2.70\(abto.0\)-20211208
• Zyxel Gs1900-24Hp Firmware: before 2.70\(aahm.0\)-20211208 — fixed in 2.70\(aahm.0\)-20211208
• Zyxel GS1900-24HPv2 firmware: before 2.70\(aatp.0\)-20211208 — fixed in 2.70\(aatp.0\)-20211208
• Zyxel GS1900-48 firmware: before 2.70\(aahn.0\)-20211208 — fixed in 2.70\(aahn.0\)-20211208
• Zyxel Gs1900-48Hp Firmware: before 2.70\(aaho.0\)-20211208 — fixed in 2.70\(aaho.0\)-20211208
• Zyxel GS1900-48HPv2 firmware: before 2.70\(abtq.0\)-20211208 — fixed in 2.70\(abtq.0\)-20211208
• Zyxel GS1900-8 firmware: before 2.70\(aahh.0\)-20211208 — fixed in 2.70\(aahh.0\)-20211208
• Zyxel GS1900-8HP firmware: before 2.70\(aahi.0\)-20211208 — fixed in 2.70\(aahi.0\)-20211208

How to fix

Upgrade to a fixed version: Zyxel GS1900-10HP firmware 2.70\(aazi.0\)-20211208; Zyxel GS1900-16 firmware 2.70\(aahj.0\)-20211208; Zyxel GS1900-24 firmware 2.70\(aahl.0\)-20211208; Zyxel GS1900-24E firmware 2.70\(aahk.0\)-20211208; Zyxel GS1900-24EP firmware 2.70\(abto.0\)-20211208; Zyxel Gs1900-24Hp Firmware 2.70\(aahm.0\)-20211208; Zyxel GS1900-24HPv2 firmware 2.70\(aatp.0\)-20211208; Zyxel GS1900-48 firmware 2.70\(aahn.0\)-20211208; Zyxel Gs1900-48Hp Firmware 2.70\(aaho.0\)-20211208; Zyxel GS1900-48HPv2 firmware 2.70\(abtq.0\)-20211208; Zyxel GS1900-8 firmware 2.70\(aahh.0\)-20211208; Zyxel GS1900-8HP firmware 2.70\(aahi.0\)-20211208. Check the vendor advisory for mitigations.

References

• https://www.zyxel.com/support/Zyxel_security_advisory_for_OS_command_injection_vulnerabilities_of_switches.shtml
• https://www.zyxel.com/support/Zyxel_security_advisory_for_OS_command_injection_vulnerabilities_of_switches.shtml

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