An update for dovecot is now available for HCE 2.0 Security Advisory hws_security@huawei.com Huawei Cloud HCE2-SA-2024-0272 Final 1.0 1.0 2024-11-19T07:40:47:00Z current version 2024-11-19T07:40:47:00Z 2024-11-19T07:40:47:00Z HCE SA Engine 1.0.0 An update for dovecot is now available for HCE 2.0 HCE Security has rated this update as having a security impact of Important.A Common Vunlnerability Scoring System(CVSS)base score, which gives a detailed severity rating, is available for each vulnerability from the CVElink(s) in the References section. Security Fix(es): Very large headers can cause resource exhaustion when parsing message. The message-parser normally reads reasonably sized chunks of the message. However, when it feeds them to message-header-parser, it starts building up "full_value" buffer out of the smaller chunks. The full_value buffer has no size limit, so large headers can cause large memory usage. It doesn_x27;t matter whether it_x27;s a single long header line, or a single header split into multiple lines. This bug exists in all Dovecot versions. Incoming mails typically have some size limits set by MTA, so even largest possible header size may still fit into Dovecot_x27;s vsz_limit. So attackers probably can_x27;t DoS a victim user this way. A user could APPEND larger mails though, allowing them to DoS themselves (although maybe cause some memory issues for the backend in general). One can implement restrictions on headers on MTA component preceding Dovecot. No publicly available exploits are known. (CVE-2024-23185) Having a large number of address headers (From, To, Cc, Bcc, etc.) becomes excessively CPU intensive. With 100k header lines CPU usage is already 12 seconds, and in a production environment we observed 500k header lines taking 18 minutes to parse. Since this can be triggered by external actors sending emails to a victim, this is a security issue. An external attacker can send specially crafted messages that consume target system resources and cause outage. One can implement restrictions on address headers on MTA component preceding Dovecot. No publicly available exploits are known. (CVE-2024-23184) This document is provided on an "AS IS" basis and does not implyany kind of guarantee or warranty, either express or implied, including the warranties of merchantability or fitness for a particular purpose. In no eventshall Huawei or any of its directly or indirectly controlled subsidiaries or its suppliers be liable for any damages whatsoever including direct, indirect, incidental, consequential, loss of business profits or special damages. Your use of the document, by any means, is totally at your own risk. Huawei is entitled to amend or update this document from time to time. The information and data embodied in this document and any attachment are strictly confidential information of Huawei and are supplied on the understanding that they will be held confidentially and not disclosed to third parties without the prior written consent of Huawei. Use all reasonable efforts to protect the confidentiality of information. In particular, do not directly or indirectly disclose, allow access to, transmit or transfer information to a third party without our prior written consent. Thank you for your co-operation. Receipt of this security advisory shall be deemed as your consent of the terms and conditions above. Huawei Cloud EulerOS 2.0 dovecot This vulnerability can be exploited only when the following conditions are present: None Vulnerability details: For technical details, customers are advised to reference the website: https://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2024-23185 CVE-2024-23185 HCE 2.0:dovecot-2.3.15-5.r1.hce2 For technical details, customers are advised to referencethe website: https://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2024-23185 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H This vulnerability can be exploited only when the following conditions are present: None Vulnerability details: For technical details, customers are advised to reference the website: https://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2024-23184 CVE-2024-23184 HCE 2.0:dovecot-2.3.15-5.r1.hce2 For technical details, customers are advised to referencethe website: https://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2024-23184 5.0 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:L/A:N