High severity · published Sep 1, 2021
CVE-2021-33582
Cyrus IMAP before 3.4.2 allows remote attackers to cause a denial of service (multiple-minute daemon hang) via input that is mishandled during hash-table interaction
7.5
CVSS
3.1%
EPSS
No
On KEV
Description
Cyrus IMAP before 3.4.2 allows remote attackers to cause a denial of service (multiple-minute daemon hang) via input that is mishandled during hash-table interaction. Because there are many insertions into a single bucket, strcmp becomes slow. This is fixed in 3.4.2, 3.2.8, and 3.0.16.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
None
Integrity
None
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)3.1% · higher than 88% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
DL
Debian Linux · Debian
9.0 · source: NVD
FE
Fedora · Fedoraproject
34; 35 · source: NVD
IM
Imap · Cyrus
before 3.0.16; 3.2.0 before 3.2.8; 3.4.0 before 3.4.2 · source: NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2021-33582
CVE.org
https://www.cve.org/CVERecord?id=CVE-2021-33582
Patch
https://cyrus.topicbox.com/groups/announce/T3dde0a2352462975-M1386fc44adf967e072f8df13/cyrus-imap-3-4-2-3-2-8-and-3-0-16-released
Patch
https://github.com/cyrusimap/cyrus-imapd/commits/master
Not Applicable
https://github.com/cyrusimap/cyrus-imapd/security/advisories
Mailing List
https://lists.debian.org/debian-lts-announce/2022/06/msg00013.html
lists.fedoraproject.org
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/6HEO3RURJW6NLIXS7NK5PVU6MGHC4SCM/
lists.fedoraproject.org
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/WJZB45QBUN7CZFGOWCZYUYACNBTX7LVS/
More from Imap
9.8
CVE-2019-18928
Cyrus IMAP 2.5.x before 2.5.14 and 3.x before 3.0.12 allows privilege escalation because an HTTP request may be interpreted in the authentication context of an unrelated previous…
9.8
CVE-2019-11356
The CalDAV feature in httpd in Cyrus IMAP 2.5.x through 2.5.12 and 3.0.x through 3.0.9 allows remote attackers to execute arbitrary code via a crafted HTTP PUT operation for an…
9.1
CVE-2017-14230
In the mboxlist_do_find function in imap/mboxlist.c in Cyrus IMAP before 3.0.4, an off-by-one error in prefix calculation for the LIST command caused use of uninitialized memory,…
7.1
CVE-2026-61915
An issue was discovered in Cyrus IMAP before 3.12.4
6.5
CVE-2026-61908
An issue was discovered in Cyrus IMAP before 3.12.4