CVE-2020-8299

Severity: medium (CVSS 6.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.4% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2021-06-16 · updated 2026-06-17
Weakness: CWE-400

Description

Citrix ADC and Citrix/NetScaler Gateway 13.0 before 13.0-76.29, 12.1-61.18, 11.1-65.20, Citrix ADC 12.1-FIPS before 12.1-55.238, and Citrix SD-WAN WANOP Edition before 11.4.0, 11.3.2, 11.3.1a, 11.2.3a, 11.1.2c, 10.2.9a suffers from uncontrolled resource consumption by way of a network-based denial-of-service from within the same Layer 2 network segment. Note that the attacker must be in the same Layer 2 network segment as the vulnerable appliance.

Affected products

Citrix Application Delivery Controller Firmware: from 11.1 before 11.1-65.20; from 12.1 before 12.1-61.18; from 13.0 before 13.0-76.29; from 12.1 before 12.1-55.238 — fixed in 11.1-65.20, 12.1-61.18, 13.0-76.29, 12.1-55.238
NetScaler Gateway: from 12.1 before 12.1-61.18; from 13.0 before 13.0-76.29 — fixed in 12.1-61.18, 13.0-76.29
Citrix NetScaler Gateway: from 11.1 before 11.1-65.20 — fixed in 11.1-65.20
Citrix Sd-Wan Wanop: from 10.2 before 10.2.9a; from 11.1 before 11.1.2c; from 11.2 before 11.2.3a; from 11.3 before 11.3.2 — fixed in 10.2.9a, 11.1.2c, 11.2.3a, 11.3.2
Citrix ADC, Citrix Gateway, Citrix SD-WAN WANOP Edition: Fixed in Citrix ADC and Citrix Gateway 13.0-76.29 and later releases of 13.0, Citrix ADC and Citrix Gateway 12.1-61.18 and later releases of 12.1, Citrix ADC and NetScaler Gateway 11.1-65.20 and later releases of 11.1, Citrix ADC 12.1-FIPS 12.1-55.238 and later releases of 12.1-FIPS, Citrix SD-WAN WANOP 11.4.0 and later releases of 11.4, Citrix SD-WAN WANOP 11.3.2 and later releases of 11.3, Citrix SD-WAN WANOP 11.3.1a and later releases of 11.3, Citrix SD-WAN WANOP 11.2.3a and later releases of 11.2, Citrix SD-WAN WANOP 11.1.2c and later releases of 11.1, Citrix SD-WAN WANOP 10.2.9a and later releases of 10.2

How to fix

Upgrade to a fixed version: Citrix Application Delivery Controller Firmware 11.1-65.20, 12.1-61.18, 13.0-76.29, 12.1-55.238; NetScaler Gateway 12.1-61.18, 13.0-76.29; Citrix NetScaler Gateway 11.1-65.20; Citrix Sd-Wan Wanop 10.2.9a, 11.1.2c, 11.2.3a, 11.3.2. Check the vendor advisory for mitigations.

References

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