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ID

VDE-2024-029

Published

2024-06-11 08:00 (CEST)

Last update

2024-06-11 09:17 (CEST)

Vendor(s)

PHOENIX CONTACT GmbH & Co. KG

Product(s)

Article No┬░ Product Name Affected Version(s)
1153079 FL MGUARD 1102 < 1.8.0
1153078 FL MGUARD 1105 < 1.8.0

Summary

The OpenSSL library used in the affected products is vulnerable to an unbounded growth of the session cache in the TLSv1.3 implementation.


CVE ID

CVE-2024-2511

Last Update:

June 6, 2024, 11:54 a.m.

Weakness

Allocation of Resources Without Limits or Throttling  (CWE-770) 

Summary

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.

Details

cve.org 

Impact

A remote attacker can exhaust all memory by establishing a large number of TLSv1.3 connections to the web interface, causing the device to reboot.

Solution

Mitigation

Phoenix Contact recommends that customers restrict network access to the device's web interface to as few networks as possible.

Remediation

Phoenix Contact recommends upgrading the firmware of affected devices to version 1.8.0 or higher, which fixes the vulnerability.

Reported by

CERT@VDE coordinated with Phoenix Contact.