Red Hat Single Sign-On 7.6 for RHEL 7: Allocation of Resources Without Limits or Throttling
CVE-2023-6563 is a high-severity allocation of resources without limits or throttling vulnerability in Red Hat Single Sign-On 7.6 for RHEL 7 from Red Hat, with a CVSS 3.1 base score of 7.7 out of 10. It can be exploited remotely over the network by an attacker with a low-privileged account, without any action from a user. There is no confirmed exploitation so far. EPSS estimates a 1.24% chance of exploitation within 30 days, higher than 70% of scored CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update Keycloak to 21.0.0 or a later version.
- Read the advisory on access.redhat.com for workarounds and exact fixed builds.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Red Hat | Red Hat Single Sign-On 7.6 for RHEL 7 | Not specified in the record | Not stated |
| Red Hat | Red Hat Single Sign-On 7.6 for RHEL 8 | Not specified in the record | Not stated |
| Red Hat | Red Hat Single Sign-On 7.6 for RHEL 9 | Not specified in the record | Not stated |
| Red Hat | RHEL-8 based Middleware Containers | Not specified in the record | Not stated |
| Red Hat | Single Sign-On 7.6.6 | Not specified in the record | Not stated |
| Red Hat | Red Hat Build of Keycloak | Not specified in the record | Not stated |
| Red Hat | Keycloak | before 21.0.0 | 21.0.0 |
| Red Hat | Single Sign-on | 7.6 | Not stated |
| Red Hat | Openshift Container Platform | 4.11; 4.12 | Not stated |
| Red Hat | Openshift Container Platform For Power | 4.9; 4.10 | Not stated |
| Red Hat | Openshift Container Platform For IBM Linuxone | 4.9; 4.10 | 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
- NoneNo action by a victim is required.
- Scope
- ChangedThe attack can reach beyond the vulnerable component into other systems.
- 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:L/UI:N/S:C/C:N/I:N/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 7.7 | High | CNA (redhat.com) |
| CVSS 3.1 | 7.7 | High | NVD |
Official description
An unconstrained memory consumption vulnerability was discovered in Keycloak. It can be triggered in environments which have millions of offline tokens (> 500,000 users with each having at least 2 saved sessions). If an attacker creates two or more user sessions and then open the "consents" tab of the admin User Interface, the UI attempts to load a huge number of offline client sessions leading to excessive memory and CPU consumption which could potentially crash the entire system.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Allocation of Resources Without Limits or Throttling
The product allocates a reusable resource or group of resources on behalf of an actor without imposing any intended restrictions on the size or number of resources that can be allocated.
How developers prevent this class of flaw
- Clearly specify the minimum and maximum expectations for capabilities, and dictate which behaviors are acceptable when resource allocation reaches limits.
- Limit the amount of resources that are accessible to unprivileged users. Set per-user limits for resources. Allow the system administrator to define these limits. Be careful to avoid CWE-410.
- For any security checks that are performed on the client side, ensure that these checks are duplicated on the server side, in order to avoid CWE-602. Attackers can bypass the client-side checks by modifying values after the checks have been performed, or by changing the client to remove the client-side checks entirely. Then, these modified values would be submitted to the server.
More Allocation of Resources Without Limits or Throttling vulnerabilities (CWE-770)
Timeline
- CVE record published.
- Record last changed materially (score, affected products, status or references).
References
Advisories
Technical write-ups (may include proof of concept)
Other references
- bugzilla.redhat.com/show_bug.cgi?id=2253308Issue Tracking
- github.com/keycloak/keycloak/issues/13340Issue Tracking
Other vulnerabilities in Red Hat Single Sign-On 7.6 for RHEL 7
- 9.1 Critical severity
- 7.4 High severity
- 7.5 High severity
- 7.5 High severity
- 7.5 High severity
- 7.7 High severity
Recent Allocation of Resources Without Limits or Throttling 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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