Citrix Application Delivery Controller (ADC) and Gateway Authentication Bypass
CVE-2022-27518 is a critical-severity improper control of a resource through its lifetime vulnerability in Citrix Gateway, Citrix ADC from Citrix, with a CVSS 3.1 base score of 9.8 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected Citrix Gateway, Citrix ADC versions: 12.1; 13.0; 12.1 FIPs, NDcPP. The record does not name a fixed version, so check the vendor advisory. CISA added it to the Known Exploited Vulnerabilities catalogue on December 13, 2022, which means attacks have been observed in the wild.
Attackers are already exploiting this vulnerability, according to CISA.
What to do
- Update Application Delivery Controller Firmware to 12.1-55.291 or 12.1-65.25 or 13.0-58.32, whichever matches your release line, or a later version.
- Update Gateway Firmware to 12.1-65.25 or 13.0-58.32, whichever matches your release line, or a later version.
- CISA's required action: Apply updates per vendor instructions.
- Read the advisory on support.citrix.com for workarounds and exact fixed builds.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Citrix | Citrix Gateway, Citrix ADC | 12.1; 13.0; 12.1 FIPs, NDcPP | Not stated |
| Citrix | Application Delivery Controller Firmware | 12.1 up to, but not including, 12.1-55.291; 12.1 up to, but not including, 12.1-65.25; 13.0 up to, but not including, 13.0-58.32 | 12.1-55.291, 12.1-65.25, 13.0-58.32 |
| Citrix | Gateway Firmware | 12.1 up to, but not including, 12.1-65.25; 13.0 up to, but not including, 13.0-58.32 | 12.1-65.25, 13.0-58.32 |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 9.8 | Critical | CNA (citrix.com) |
| CVSS 3.1 | 9.8 | Critical | NVD |
Official description
Unauthenticated remote arbitrary code execution
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Control of a Resource Through its Lifetime
The product does not maintain or incorrectly maintains control over a resource throughout its lifetime of creation, use, and release.
More Improper Control of a Resource Through its Lifetime vulnerabilities (CWE-664)
Timeline
- CVE record published.
- Added to CISA's Known Exploited Vulnerabilities catalogue.
- Deadline for US federal agencies to remediate, set by CISA.
- CISA published its SSVC assessment (exploitation: active, automatable: yes, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Advisories
Third-party and government advisories
- cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2022-27518US Government Resource
Recent Improper Control of a Resource Through its Lifetime vulnerabilities
- 7.5 High severity
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