support_uri parameter in the WARP client local settings file (mdm.xml) lacked proper…
CVE-2022-4428 is a high-severity improper input validation vulnerability in WARP from Cloudflare, with a CVSS 3.1 base score of 8.0 out of 10. It can be exploited remotely over the network by an attacker with a low-privileged account, but only if a user takes part, for example by opening a link or file. Affected WARP versions: 2022.10.106.0 and earlier. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.74% chance of exploitation within 30 days, higher than 55% of scored CVEs.
High severity with no evidence of exploitation so far.
What to do
- Check which version of WARP you run against the affected versions below, and install the vendor's latest release.
- Read the advisory on github.com for workarounds and exact fixed builds.
- Because the attack needs a user to take part, warn users about unexpected links and files related to this product until it is patched.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Cloudflare | WARP | 2022.10.106.0 and earlier | Not stated |
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
- LowA basic user account is enough.
- User interaction
- RequiredA user must take an action such as opening a file or link.
- 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:L/UI:R/S:U/C:H/I:H/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 8.9 | High | CNA (cloudflare.com) |
| CVSS 3.1 | 8.0 | High | NVD |
Official description
support_uri parameter in the WARP client local settings file (mdm.xml) lacked proper validation which allowed for privilege escalation and launching an arbitrary executable on the local machine upon clicking on the "Send feedback" option. An attacker with access to the local file system could use a crafted XML config file pointing to a malicious file or set a local path to the executable using Cloudflare Zero Trust Dashboard (for Zero Trust enrolled clients).
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Input Validation
The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.
How developers prevent this class of flaw
- Consider using language-theoretic security (LangSec) techniques that characterize inputs using a formal language and build recognizers for that language. This effectively requires parsing to be a distinct layer that effectively enforces a boundary between raw input and internal data representations, instead of allowing parser code to be scattered throughout the program, where it could be subject to errors or inconsistencies that create weaknesses.
- Use an input validation framework such as Struts or the OWASP ESAPI Validation API. Note that using a framework does not automatically address all input validation problems; be mindful of weaknesses that could arise from misusing the framework itself (CWE-1173).
- Understand all the potential areas where untrusted inputs can enter the product, including but not limited to: parameters or arguments, cookies, anything read from the network, environment variables, reverse DNS lookups, query results, request headers, URL components, e-mail, files, filenames, databases, and any external systems that provide data to the application. Remember that such inputs may be obtained indirectly through API calls.
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Advisories
- github.com/cloudflare/advisories/security/advisories/GHSA-h3j3-fhqg-66rhProduct, Third Party Advisory
Other vulnerabilities in WARP
- 7.1 High severity
- 7.3 High severity
- 7.8 High severity
- 7.8 High severity
- 8.8 High severity
- 8.5 High severity
Recent Improper Input Validation vulnerabilities
- 8.8 High severity
- 7.5 High severity
- 9.8 Critical severity
- 7.9 High severity
- 7.5 High severity
- 7.5 High severity
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