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Vulnerability record · CVE-2021-28994 · published 31 March 2021

CVE-2021-28994: Kopano groupware core allocation without limits vulnerability

Kopano · Groupware Core

kopano-ical (formerly zarafa-ical) in Kopano Groupware Core through 8.7.16, 9.x through 9.1.0, 10.x through 10.0.7, and 11.x through 11.0.1 and Zarafa 6.30.x through 7.2.x allows memory exhaustion via long HTTP headers.

7.5 CVSS 3.1 High EPSS 2.0% · top 19.6% CWE-770 · Allocation without limits
7.5CVSS 3.1 base score, v2 5.0
2.0%EPSS exploitation probability, 30 days
NoNot in CISA KEV
2Affected product versions listed by NVD
6References, 2 tagged exploit
17 Jun 2026Last modified by NVD

Description

kopano-ical (formerly zarafa-ical) in Kopano Groupware Core through 8.7.16, 9.x through 9.1.0, 10.x through 10.0.7, and 11.x through 11.0.1 and Zarafa 6.30.x through 7.2.x allows memory exhaustion via long HTTP headers.

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected products

2 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

LinkTags
http://www.openwall.com/lists/oss-security/2021/04/01/1 Mailing ListThird Party Advisory
http://www.openwall.com/lists/oss-security/2021/04/25/1 Mailing ListThird Party Advisory
https://www.openwall.com/lists/oss-security/2021/03/19/6 ExploitMailing ListThird Party Advisory
http://www.openwall.com/lists/oss-security/2021/04/01/1 Mailing ListThird Party Advisory
http://www.openwall.com/lists/oss-security/2021/04/25/1 Mailing ListThird Party Advisory
https://www.openwall.com/lists/oss-security/2021/03/19/6 ExploitMailing ListThird Party Advisory

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Related vulnerabilities

Same products first, then exploited flaws of the same weakness class.

9.8CVE-2022-26562Kopano groupware core improper authentication vulnerabilityAn issue in provider/libserver/ECKrbAuth.cpp of Kopano Core <= v11.0.2.51 contains an issue which allows attackers to authenticate even if the user a…EPSS 2.2%9.8CVE-2019-19907Kopano groupware core classic buffer overflow vulnerabilityHrAddFBBlock in libfreebusy/freebusyutil.cpp in Kopano Groupware Core before 8.7.7 allows out-of-bounds access, as demonstrated by mishandling of an …EPSS 2.2%5.0CVE-2014-0037Zarafa improper input validation vulnerabilityThe ValidateUserLogon function in provider/libserver/ECSession.cpp in Zarafa 5.00 before 7.1.8 beta2 allows remote attackers to cause a denial of ser…EPSS 2.4%5.0CVE-2014-0079Zarafa improper input validation vulnerabilityThe ValidateUserLogon function in provider/libserver/ECSession.cpp in Zarafa 7.1.8, 6.20.0, and earlier, when using certain build conditions, allows …EPSS 1.8%2.1CVE-2014-5447Zarafa webapp information exposure vulnerabilityZarafa WebAccess 7.1.10 and WebApp 1.6 beta uses weak permissions (644) for config.php, which allows local users to obtain sensitive information by r…EPSS 0.37%2.1CVE-2014-5448Zarafa information exposure vulnerabilityZarafa 5.00 uses world-readable permissions for the files in the log directory, which allows local users to obtain sensitive information by reading t…EPSS 0.37%2.1CVE-2014-0103Zarafa webapp vulnerabilityWebAccess in Zarafa before 7.1.10 and WebApp before 1.6 stores credentials in cleartext, which allows local Apache users to obtain sensitive informat…EPSS 0.38%8.6CVE-2020-3569Cisco IOS XR DVMRP IGMP packet handling memory exhaustionCisco IOS XR Software mishandles IGMP packets in its Distance Vector Multicast Routing Protocol (DVMRP) feature, allowing crafted traffic to crash th…KEVEPSS 3.3%analysed

Source: NIST National Vulnerability Database (record CVE-2021-28994), CISA KEV, FIRST EPSS (scores of 2026-09-27). This page is refreshed as NVD updates the record.