Varnish Cache: Uncontrolled Resource Consumption
CVE-2022-38150 is a high-severity uncontrolled resource consumption vulnerability in Varnish Cache from Varnish Cache Project, with a CVSS 3.1 base score of 7.5 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected Varnish Cache versions: 7.0.0; 7.0.1; 7.0.2, and others listed below. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 1.5% chance of exploitation within 30 days, higher than 75% of scored CVEs.
High severity with no evidence of exploitation so far.
What to do
- Check which version of Varnish Cache you run against the affected versions below, and install the vendor's latest release.
- Read the advisory on varnish-cache.org 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 |
|---|---|---|---|
| Varnish Cache Project | Varnish Cache | 7.0.0; 7.0.1; 7.0.2; 7.1.0 | Not stated |
| Fedora Project | Fedora | 35; 36 | Not stated |
Version data comes from NVD's product matching. 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
- NoneNo data is disclosed.
- Integrity
- NoneNothing can be modified.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 7.5 | High | NVD |
| CVSS 3.1 | 6.5 | Medium | CISA (ADP) |
Official description
In Varnish Cache 7.0.0, 7.0.1, 7.0.2, and 7.1.0, it is possible to cause the Varnish Server to assert and automatically restart through forged HTTP/1 backend responses. An attack uses a crafted reason phrase of the backend response status line. This is fixed in 7.0.3 and 7.1.1.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Uncontrolled Resource Consumption
The product does not properly control the allocation and maintenance of a limited resource.
How developers prevent this class of flaw
- Ensure that protocols have specific limits of scale placed on them.
- Ensure that all failures in resource allocation place the system into a safe posture.
More Uncontrolled Resource Consumption vulnerabilities (CWE-400)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: partial).
- Record last changed materially (score, affected products, status or references).
References
Advisories
- varnish-cache.org/security/VSV00009.htmlMitigation
Other references
- lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/M4KVVCIQVINQQ2D7ORNA…
- lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/TW3X4PEKC5C736SCKE2U…
- lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/V2BUKFICLZBXESLQ3MXM…
Other vulnerabilities in Varnish Cache
- 7.5 High severity
Recent Uncontrolled Resource Consumption vulnerabilities
- 7.5 High severity
- 7.5 High severity
- 7.5 High severity
- 7.5 High severity
- 7.5 High severity
- 7.5 High severity
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