Bug 2274020 (CVE-2024-2511)

Summary:	CVE-2024-2511 openssl: Unbounded memory growth with session handling in TLSv1.3
Product:	[Other] Security Response	Reporter:	Marco Benatto <mbenatto>
Component:	vulnerability	Assignee:	Product Security <prodsec-ir-bot>
Status:	NEW ---	QA Contact:
Severity:	low	Docs Contact:
Priority:	low
Version:	unspecified	Keywords:	Security
Target Milestone:	---
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:	OpenSSL 3.2.2, OpenSSL 3.1.6, OpenSSL 3.0.14, OpenSSL 1.1.1y	Doc Type:	If docs needed, set a value
Doc Text:	A flaw was found in OpenSSL. A malicious client can trigger an uncontrolled memory consumption, resulting in a Denial of Service. This issue occurs due to the OpenSSL's TLSv3.1 session cache going into an incorrect state, leading to it failing to flush properly as it fills. OpenSSL must be configured with the non-default SSL_OP_NO_TICKET option enabled to be vulnerable. This issue only affects TLSv1.3 servers, while TLS clients are not affected.	Story Points:	---
Clone Of:		Environment:
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Regression:	---	Mount Type:	---
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Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:
Bug Depends On:	2274021, 2274022, 2274023, 2274024
Bug Blocks:	2274025

Description Marco Benatto 2024-04-08 15:28:23 UTC

Some non-default TLS server configurations can cause unbounded memory growth when processing TLSv1.3 sessions Impact summary: An attacker may exploit certain server configurations to trigger unbounded memory growth that would lead to a Denial of Service This problem can occur in TLSv1.3 if the non-default SSL_OP_NO_TICKET option is being used (but not if early_data support is also configured and the default anti-replay protection is in use). In this case, under certain conditions, the session cache can get into an incorrect state and it will fail to flush properly as it fills. The session cache will continue to grow in an unbounded manner. A malicious client could deliberately create the scenario for this failure to force a Denial of Service. It may also happen by accident in normal operation. This issue only affects TLS servers supporting TLSv1.3. It does not affect TLS clients. The FIPS modules in 3.2, 3.1 and 3.0 are not affected by this issue. OpenSSL 1.0.2 is also not affected by this issue.

Comment 1 Marco Benatto 2024-04-08 15:31:53 UTC

Created edk2 tracking bugs for this issue:

Affects: fedora-all [bug 2274024]


Created openssl tracking bugs for this issue:

Affects: fedora-all [bug 2274023]


Created openssl11 tracking bugs for this issue:

Affects: epel-all [bug 2274022]


Created openssl3 tracking bugs for this issue:

Affects: epel-all [bug 2274021]

Comment 3 Marco Benatto 2024-04-08 19:08:04 UTC

Upstream commit for this issue:
https://github.com/openssl/openssl/commit/7984fa683e9dfac0cad50ef2a9d5a13330222044
https://github.com/openssl/openssl/commit/21df7f04f6c4a560b4de56d10e1e58958c7e566d
https://github.com/openssl/openssl/commit/4a3e8f08306c64366318e26162ae0a0eb7b1a006