CVE-2023-23621
First published: Sat Jan 28 2023(Updated: )
Discourse is an open-source discussion platform. Prior to version 3.0.1 on the `stable` branch and version 3.1.0.beta2 on the `beta` and `tests-passed` branches, a malicious user can cause a regular expression denial of service using a carefully crafted user agent. This issue is patched in version 3.0.1 on the `stable` branch and version 3.1.0.beta2 on the `beta` and `tests-passed` branches. There are no known workarounds.
Credit: security-advisories@github.com
| Affected Software | Affected Version | How to fix |
|---|---|---|
| Discourse | <3.0.1 | |
| Discourse | =1.1.0-beta1 | |
| Discourse | =1.1.0-beta2 | |
| Discourse | =1.1.0-beta3 | |
| Discourse | =1.1.0-beta4 | |
| Discourse | =1.1.0-beta5 | |
| Discourse | =1.1.0-beta6 | |
| Discourse | =1.1.0-beta6b | |
| Discourse | =1.1.0-beta7 | |
| Discourse | =1.1.0-beta8 | |
| Discourse | =1.2.0-beta1 | |
| Discourse | =1.2.0-beta2 | |
| Discourse | =1.2.0-beta3 | |
| Discourse | =1.2.0-beta4 | |
| Discourse | =1.2.0-beta5 | |
| Discourse | =1.2.0-beta6 | |
| Discourse | =1.2.0-beta7 | |
| Discourse | =1.2.0-beta8 | |
| Discourse | =1.2.0-beta9 | |
| Discourse | =1.3.0-beta1 | |
| Discourse | =1.3.0-beta10 | |
| Discourse | =1.3.0-beta11 | |
| Discourse | =1.3.0-beta2 | |
| Discourse | =1.3.0-beta3 | |
| Discourse | =1.3.0-beta4 | |
| Discourse | =1.3.0-beta5 | |
| Discourse | =1.3.0-beta6 | |
| Discourse | =1.3.0-beta7 | |
| Discourse | =1.3.0-beta8 | |
| Discourse | =1.3.0-beta9 | |
| Discourse | =1.4.0-beta1 | |
| Discourse | =1.4.0-beta10 | |
| Discourse | =1.4.0-beta11 | |
| Discourse | =1.4.0-beta12 | |
| Discourse | =1.4.0-beta2 | |
| Discourse | =1.4.0-beta3 | |
| Discourse | =1.4.0-beta4 | |
| Discourse | =1.4.0-beta5 | |
| Discourse | =1.4.0-beta6 | |
| Discourse | =1.4.0-beta7 | |
| Discourse | =1.4.0-beta8 | |
| Discourse | =1.4.0-beta9 | |
| Discourse | =1.5.0-beta1 | |
| Discourse | =1.5.0-beta10 | |
| Discourse | =1.5.0-beta11 | |
| Discourse | =1.5.0-beta12 | |
| Discourse | =1.5.0-beta13 | |
| Discourse | =1.5.0-beta13b | |
| Discourse | =1.5.0-beta14 | |
| Discourse | =1.5.0-beta2 | |
| Discourse | =1.5.0-beta3 | |
| Discourse | =1.5.0-beta4 | |
| Discourse | =1.5.0-beta5 | |
| Discourse | =1.5.0-beta6 | |
| Discourse | =1.5.0-beta7 | |
| Discourse | =1.5.0-beta8 | |
| Discourse | =1.5.0-beta9 | |
| Discourse | =1.6.0-beta1 | |
| Discourse | =1.6.0-beta10 | |
| Discourse | =1.6.0-beta11 | |
| Discourse | =1.6.0-beta12 | |
| Discourse | =1.6.0-beta2 | |
| Discourse | =1.6.0-beta3 | |
| Discourse | =1.6.0-beta4 | |
| Discourse | =1.6.0-beta5 | |
| Discourse | =1.6.0-beta6 | |
| Discourse | =1.6.0-beta7 | |
| Discourse | =1.6.0-beta8 | |
| Discourse | =1.6.0-beta9 | |
| Discourse | =1.7.0-beta1 | |
| Discourse | =1.7.0-beta10 | |
| Discourse | =1.7.0-beta11 | |
| Discourse | =1.7.0-beta2 | |
| Discourse | =1.7.0-beta3 | |
| Discourse | =1.7.0-beta4 | |
| Discourse | =1.7.0-beta5 | |
| Discourse | =1.7.0-beta6 | |
| Discourse | =1.7.0-beta7 | |
| Discourse | =1.7.0-beta8 | |
| Discourse | =1.7.0-beta9 | |
| Discourse | =1.8.0-beta1 | |
| Discourse | =1.8.0-beta10 | |
| Discourse | =1.8.0-beta11 | |
| Discourse | =1.8.0-beta12 | |
| Discourse | =1.8.0-beta13 | |
| Discourse | =1.8.0-beta2 | |
| Discourse | =1.8.0-beta3 | |
| Discourse | =1.8.0-beta4 | |
| Discourse | =1.8.0-beta5 | |
| Discourse | =1.8.0-beta6 | |
| Discourse | =1.8.0-beta7 | |
| Discourse | =1.8.0-beta8 | |
| Discourse | =1.8.0-beta9 | |
| Discourse | =1.9.0-beta1 | |
| Discourse | =1.9.0-beta10 | |
| Discourse | =1.9.0-beta11 | |
| Discourse | =1.9.0-beta12 | |
| Discourse | =1.9.0-beta13 | |
| Discourse | =1.9.0-beta14 | |
| Discourse | =1.9.0-beta15 | |
| Discourse | =1.9.0-beta16 | |
| Discourse | =1.9.0-beta17 | |
| Discourse | =1.9.0-beta2 | |
| Discourse | =1.9.0-beta3 | |
| Discourse | =1.9.0-beta4 | |
| Discourse | =1.9.0-beta5 | |
| Discourse | =1.9.0-beta6 | |
| Discourse | =1.9.0-beta7 | |
| Discourse | =1.9.0-beta8 | |
| Discourse | =1.9.0-beta9 | |
| Discourse | =2.0.0-beta1 | |
| Discourse | =2.0.0-beta10 | |
| Discourse | =2.0.0-beta2 | |
| Discourse | =2.0.0-beta3 | |
| Discourse | =2.0.0-beta4 | |
| Discourse | =2.0.0-beta5 | |
| Discourse | =2.0.0-beta6 | |
| Discourse | =2.0.0-beta7 | |
| Discourse | =2.0.0-beta8 | |
| Discourse | =2.0.0-beta9 | |
| Discourse | =2.1.0-beta1 | |
| Discourse | =2.1.0-beta2 | |
| Discourse | =2.1.0-beta3 | |
| Discourse | =2.1.0-beta4 | |
| Discourse | =2.1.0-beta5 | |
| Discourse | =2.1.0-beta6 | |
| Discourse | =2.2.0-beta1 | |
| Discourse | =2.2.0-beta10 | |
| Discourse | =2.2.0-beta2 | |
| Discourse | =2.2.0-beta3 | |
| Discourse | =2.2.0-beta4 | |
| Discourse | =2.2.0-beta5 | |
| Discourse | =2.2.0-beta6 | |
| Discourse | =2.2.0-beta7 | |
| Discourse | =2.2.0-beta8 | |
| Discourse | =2.2.0-beta9 | |
| Discourse | =2.3.0-beta1 | |
| Discourse | =2.3.0-beta10 | |
| Discourse | =2.3.0-beta11 | |
| Discourse | =2.3.0-beta2 | |
| Discourse | =2.3.0-beta3 | |
| Discourse | =2.3.0-beta4 | |
| Discourse | =2.3.0-beta5 | |
| Discourse | =2.3.0-beta6 | |
| Discourse | =2.3.0-beta7 | |
| Discourse | =2.3.0-beta8 | |
| Discourse | =2.3.0-beta9 | |
| Discourse | =2.4.0-beta1 | |
| Discourse | =2.4.0-beta10 | |
| Discourse | =2.4.0-beta11 | |
| Discourse | =2.4.0-beta2 | |
| Discourse | =2.4.0-beta3 | |
| Discourse | =2.4.0-beta4 | |
| Discourse | =2.4.0-beta5 | |
| Discourse | =2.4.0-beta6 | |
| Discourse | =2.4.0-beta7 | |
| Discourse | =2.4.0-beta8 | |
| Discourse | =2.4.0-beta9 | |
| Discourse | =2.5.0-beta1 | |
| Discourse | =2.5.0-beta2 | |
| Discourse | =2.5.0-beta3 | |
| Discourse | =2.5.0-beta4 | |
| Discourse | =2.5.0-beta5 | |
| Discourse | =2.5.0-beta6 | |
| Discourse | =2.5.0-beta7 | |
| Discourse | =2.6.0-beta1 | |
| Discourse | =2.6.0-beta2 | |
| Discourse | =2.6.0-beta3 | |
| Discourse | =2.6.0-beta4 | |
| Discourse | =2.6.0-beta5 | |
| Discourse | =2.6.0-beta6 | |
| Discourse | =2.7.0-beta1 | |
| Discourse | =2.7.0-beta2 | |
| Discourse | =2.7.0-beta3 | |
| Discourse | =2.7.0-beta4 | |
| Discourse | =2.7.0-beta5 | |
| Discourse | =2.7.0-beta6 | |
| Discourse | =2.7.0-beta7 | |
| Discourse | =2.7.0-beta8 | |
| Discourse | =2.7.0-beta9 | |
| Discourse | =2.8.0-beta1 | |
| Discourse | =2.8.0-beta10 | |
| Discourse | =2.8.0-beta11 | |
| Discourse | =2.8.0-beta2 | |
| Discourse | =2.8.0-beta3 | |
| Discourse | =2.8.0-beta4 | |
| Discourse | =2.8.0-beta5 | |
| Discourse | =2.8.0-beta6 | |
| Discourse | =2.8.0-beta7 | |
| Discourse | =2.8.0-beta8 | |
| Discourse | =2.8.0-beta9 | |
| Discourse | =2.9.0-beta1 | |
| Discourse | =2.9.0-beta10 | |
| Discourse | =2.9.0-beta11 | |
| Discourse | =2.9.0-beta12 | |
| Discourse | =2.9.0-beta13 | |
| Discourse | =2.9.0-beta14 | |
| Discourse | =2.9.0-beta2 | |
| Discourse | =2.9.0-beta3 | |
| Discourse | =2.9.0-beta4 | |
| Discourse | =2.9.0-beta5 | |
| Discourse | =2.9.0-beta6 | |
| Discourse | =2.9.0-beta7 | |
| Discourse | =2.9.0-beta8 | |
| Discourse | =2.9.0-beta9 | |
| Discourse | =3.0.0-beta15 | |
| Discourse | =3.0.0-beta16 | |
| Discourse | =3.1.0-beta1 |
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Reference Links
Frequently Asked Questions
What is the severity of CVE-2023-23621?
CVE-2023-23621 has a critical severity rating due to its potential for regular expression denial of service attacks.
How do I fix CVE-2023-23621?
To mitigate CVE-2023-23621, upgrade to Discourse version 3.0.1 or later on the stable branch, or version 3.1.0.beta2 or later on the beta and tests-passed branches.
Who is affected by CVE-2023-23621?
Discourse users running versions prior to 3.0.1 on the stable branch and 3.1.0.beta2 on beta or tests-passed branches are affected by CVE-2023-23621.
What can attackers do with CVE-2023-23621?
Attackers can exploit CVE-2023-23621 to launch denial of service attacks by sending specially crafted user agents that trigger excessive regex processing.
Is there a patch available for CVE-2023-23621?
Yes, CVE-2023-23621 is patched in Discourse version 3.0.1 and later.
- agent/weakness
- agent/author
- agent/severity
- agent/references
- agent/last-modified-date
- agent/remedy
- agent/softwarecombine
- agent/first-publish-date
- agent/type
- agent/description
- agent/tags
- agent/event
- collector/nvd-index
- agent/software-canonical-lookup-request
- vendor/discourse
- canonical/discourse
- version/discourse/1.1.0-beta1
- version/discourse/1.1.0-beta2
- version/discourse/1.1.0-beta3
- version/discourse/1.1.0-beta4
- version/discourse/1.1.0-beta5
- version/discourse/1.1.0-beta6
- version/discourse/1.1.0-beta6b
- version/discourse/1.1.0-beta7
- version/discourse/1.1.0-beta8
- version/discourse/1.2.0-beta1
- version/discourse/1.2.0-beta2
- version/discourse/1.2.0-beta3
- version/discourse/1.2.0-beta4
- version/discourse/1.2.0-beta5
- version/discourse/1.2.0-beta6
- version/discourse/1.2.0-beta7
- version/discourse/1.2.0-beta8
- version/discourse/1.2.0-beta9
- version/discourse/1.3.0-beta1
- version/discourse/1.3.0-beta10
- version/discourse/1.3.0-beta11
- version/discourse/1.3.0-beta2
- version/discourse/1.3.0-beta3
- version/discourse/1.3.0-beta4
- version/discourse/1.3.0-beta5
- version/discourse/1.3.0-beta6
- version/discourse/1.3.0-beta7
- version/discourse/1.3.0-beta8
- version/discourse/1.3.0-beta9
- version/discourse/1.4.0-beta1
- version/discourse/1.4.0-beta10
- version/discourse/1.4.0-beta11
- version/discourse/1.4.0-beta12
- version/discourse/1.4.0-beta2
- version/discourse/1.4.0-beta3
- version/discourse/1.4.0-beta4
- version/discourse/1.4.0-beta5
- version/discourse/1.4.0-beta6
- version/discourse/1.4.0-beta7
- version/discourse/1.4.0-beta8
- version/discourse/1.4.0-beta9
- version/discourse/1.5.0-beta1
- version/discourse/1.5.0-beta10
- version/discourse/1.5.0-beta11
- version/discourse/1.5.0-beta12
- version/discourse/1.5.0-beta13
- version/discourse/1.5.0-beta13b
- version/discourse/1.5.0-beta14
- version/discourse/1.5.0-beta2
- version/discourse/1.5.0-beta3
- version/discourse/1.5.0-beta4
- version/discourse/1.5.0-beta5
- version/discourse/1.5.0-beta6
- version/discourse/1.5.0-beta7
- version/discourse/1.5.0-beta8
- version/discourse/1.5.0-beta9
- version/discourse/1.6.0-beta1
- version/discourse/1.6.0-beta10
- version/discourse/1.6.0-beta11
- version/discourse/1.6.0-beta12
- version/discourse/1.6.0-beta2
- version/discourse/1.6.0-beta3
- version/discourse/1.6.0-beta4
- version/discourse/1.6.0-beta5
- version/discourse/1.6.0-beta6
- version/discourse/1.6.0-beta7
- version/discourse/1.6.0-beta8
- version/discourse/1.6.0-beta9
- version/discourse/1.7.0-beta1
- version/discourse/1.7.0-beta10
- version/discourse/1.7.0-beta11
- version/discourse/1.7.0-beta2
- version/discourse/1.7.0-beta3
- version/discourse/1.7.0-beta4
- version/discourse/1.7.0-beta5
- version/discourse/1.7.0-beta6
- version/discourse/1.7.0-beta7
- version/discourse/1.7.0-beta8
- version/discourse/1.7.0-beta9
- version/discourse/1.8.0-beta1
- version/discourse/1.8.0-beta10
- version/discourse/1.8.0-beta11
- version/discourse/1.8.0-beta12
- version/discourse/1.8.0-beta13
- version/discourse/1.8.0-beta2
- version/discourse/1.8.0-beta3
- version/discourse/1.8.0-beta4
- version/discourse/1.8.0-beta5
- version/discourse/1.8.0-beta6
- version/discourse/1.8.0-beta7
- version/discourse/1.8.0-beta8
- version/discourse/1.8.0-beta9
- version/discourse/1.9.0-beta1
- version/discourse/1.9.0-beta10
- version/discourse/1.9.0-beta11
- version/discourse/1.9.0-beta12
- version/discourse/1.9.0-beta13
- version/discourse/1.9.0-beta14
- version/discourse/1.9.0-beta15
- version/discourse/1.9.0-beta16
- version/discourse/1.9.0-beta17
- version/discourse/1.9.0-beta2
- version/discourse/1.9.0-beta3
- version/discourse/1.9.0-beta4
- version/discourse/1.9.0-beta5
- version/discourse/1.9.0-beta6
- version/discourse/1.9.0-beta7
- version/discourse/1.9.0-beta8
- version/discourse/1.9.0-beta9
- version/discourse/2.0.0-beta1
- version/discourse/2.0.0-beta10
- version/discourse/2.0.0-beta2
- version/discourse/2.0.0-beta3
- version/discourse/2.0.0-beta4
- version/discourse/2.0.0-beta5
- version/discourse/2.0.0-beta6
- version/discourse/2.0.0-beta7
- version/discourse/2.0.0-beta8
- version/discourse/2.0.0-beta9
- version/discourse/2.1.0-beta1
- version/discourse/2.1.0-beta2
- version/discourse/2.1.0-beta3
- version/discourse/2.1.0-beta4
- version/discourse/2.1.0-beta5
- version/discourse/2.1.0-beta6
- version/discourse/2.2.0-beta1
- version/discourse/2.2.0-beta10
- version/discourse/2.2.0-beta2
- version/discourse/2.2.0-beta3
- version/discourse/2.2.0-beta4
- version/discourse/2.2.0-beta5
- version/discourse/2.2.0-beta6
- version/discourse/2.2.0-beta7
- version/discourse/2.2.0-beta8
- version/discourse/2.2.0-beta9
- version/discourse/2.3.0-beta1
- version/discourse/2.3.0-beta10
- version/discourse/2.3.0-beta11
- version/discourse/2.3.0-beta2
- version/discourse/2.3.0-beta3
- version/discourse/2.3.0-beta4
- version/discourse/2.3.0-beta5
- version/discourse/2.3.0-beta6
- version/discourse/2.3.0-beta7
- version/discourse/2.3.0-beta8
- version/discourse/2.3.0-beta9
- version/discourse/2.4.0-beta1
- version/discourse/2.4.0-beta10
- version/discourse/2.4.0-beta11
- version/discourse/2.4.0-beta2
- version/discourse/2.4.0-beta3
- version/discourse/2.4.0-beta4
- version/discourse/2.4.0-beta5
- version/discourse/2.4.0-beta6
- version/discourse/2.4.0-beta7
- version/discourse/2.4.0-beta8
- version/discourse/2.4.0-beta9
- version/discourse/2.5.0-beta1
- version/discourse/2.5.0-beta2
- version/discourse/2.5.0-beta3
- version/discourse/2.5.0-beta4
- version/discourse/2.5.0-beta5
- version/discourse/2.5.0-beta6
- version/discourse/2.5.0-beta7
- version/discourse/2.6.0-beta1
- version/discourse/2.6.0-beta2
- version/discourse/2.6.0-beta3
- version/discourse/2.6.0-beta4
- version/discourse/2.6.0-beta5
- version/discourse/2.6.0-beta6
- version/discourse/2.7.0-beta1
- version/discourse/2.7.0-beta2
- version/discourse/2.7.0-beta3
- version/discourse/2.7.0-beta4
- version/discourse/2.7.0-beta5
- version/discourse/2.7.0-beta6
- version/discourse/2.7.0-beta7
- version/discourse/2.7.0-beta8
- version/discourse/2.7.0-beta9
- version/discourse/2.8.0-beta1
- version/discourse/2.8.0-beta10
- version/discourse/2.8.0-beta11
- version/discourse/2.8.0-beta2
- version/discourse/2.8.0-beta3
- version/discourse/2.8.0-beta4
- version/discourse/2.8.0-beta5
- version/discourse/2.8.0-beta6
- version/discourse/2.8.0-beta7
- version/discourse/2.8.0-beta8
- version/discourse/2.8.0-beta9
- version/discourse/2.9.0-beta1
- version/discourse/2.9.0-beta10
- version/discourse/2.9.0-beta11
- version/discourse/2.9.0-beta12
- version/discourse/2.9.0-beta13
- version/discourse/2.9.0-beta14
- version/discourse/2.9.0-beta2
- version/discourse/2.9.0-beta3
- version/discourse/2.9.0-beta4
- version/discourse/2.9.0-beta5
- version/discourse/2.9.0-beta6
- version/discourse/2.9.0-beta7
- version/discourse/2.9.0-beta8
- version/discourse/2.9.0-beta9
- version/discourse/3.0.0-beta15
- version/discourse/3.0.0-beta16
- version/discourse/3.1.0-beta1