Arch Linux Security Advisory ASA-202101-4 ========================================= Severity: High Date : 2021-01-04 CVE-ID : CVE-2020-24386 CVE-2020-25275 Package : dovecot Type : multiple issues Remote : Yes Link : https://security.archlinux.org/AVG-1398 Summary ======= The package dovecot before version 2.3.13-1 is vulnerable to multiple issues including information disclosure and denial of service. Resolution ========== Upgrade to 2.3.13-1. # pacman -Syu "dovecot>=2.3.13-1" The problems have been fixed upstream in version 2.3.13. Workaround ========== Operators can choose to disable IMAP hibernation. IMAP hibernation is not on by default. To ensure imap hibernation is disabled, make sure imap_hibernate_timeout is set to 0 or unset. Description =========== - CVE-2020-24386 (information disclosure) A security issue was discovered in dovecot version 2.2.26 up to 2.3.11.3. When imap hibernation is active, an attacker can cause dovecot to discover the file system directory structure and access other users' emails using a specially crafted command. The attacker must have valid credentials to access the mail server. The issue is fixed in dovecot version 2.3.13. - CVE-2020-25275 (denial of service) A security issue was discovered in dovecot version 2.3.11 up to 2.3.11.3. Mail delivery/parsing crashed when the 10 000th MIME part was message/rfc822 (or if its parent was multipart/digest). This happened due to earlier MIME parsing changes for CVE-2020-12100. Malicious senders could crash dovecot repeatedly by sending/uploading messages with more than 10 000 MIME parts. The issue is fixed in dovecot version 2.3.13. Impact ====== Malicious senders could crash dovecot repeatedly by sending/uploading messages with more than 10 000 MIME parts. In addition, when imap hibernation is active, a remote, authenticated attacker can cause dovecot to discover the file system directory structure and access other users' emails using a specially crafted command. References ========== https://dovecot.org/pipermail/dovecot-news/2021-January/000450.html https://github.com/dovecot/core/commit/00df2308b0733e810824545183d73276c416c... https://github.com/dovecot/core/commit/b4a9872b833b7985c7d0e7615f1b7fc812dd4... https://dovecot.org/pipermail/dovecot-news/2021-January/000451.html https://github.com/dovecot/core/commit/67f792cb98267ee74c425772e766e7a2525c0... https://github.com/dovecot/core/commit/6ae93c3936fc870c313a6fdf44a0999d4129d... https://security.archlinux.org/CVE-2020-24386 https://security.archlinux.org/CVE-2020-25275