Description
The index_get_ids function in index.c in imapd in Cyrus IMAP Server before 2.4.11, when server-side threading is enabled, allows remote attackers to cause a denial of service (NULL pointer dereference and daemon crash) via a crafted References header in an e-mail message.
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 6.0 | cyrus-imapd-2.2 | 2.2.13-19+squeeze3 | DSA-2377-1 |
| Debian 5.0 | cyrus-imapd-2.2 | 2.2.13-14+lenny6 | DSA-2377-1 |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 6 | cyrus-imapd +2 | 2.3.16-6.el6_1.4 | RHSA-2011:1508 |
| RHEL 5 | cyrus-imapd +3 | 2.3.7-12.el5_7.2 | RHSA-2011:1508 |
| RHEL 4 | perl-Cyrus +5 | 2.2.12-17.el4 | RHSA-2011:1508 |
Advisories 2
- RHSA-2011:1508 Red Hat Security Advisory: cyrus-imapd security update Red Hat Security Advisories (RHSA) · Jun 26, 2026
- DSA-2377-1 cyrus-imapd-2.2 - denial of service Debian Security (DSA / DLA) · Mar 9, 2026