CVE-2019-19906

CVE-2019-19906 is a high-severity vulnerability in Cyrusimap Cyrus-sasl with a CVSS 3.x base score of 7.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-193.

Key facts

• Severity: High (CVSS 3.x base score 7.5)
• CVSS v2: 5.0
• EPSS exploit prediction: 8% (94th percentile)
• Actively exploited: Not listed in CISA KEV
• Weakness: CWE-193
• Affected product: Cyrusimap Cyrus-sasl
• Published: 2019-12-19
• Last modified: 2026-06-17

Description

cyrus-sasl (aka Cyrus SASL) 2.1.27 has an out-of-bounds write leading to unauthenticated remote denial-of-service in OpenLDAP via a malformed LDAP packet. The OpenLDAP crash is ultimately caused by an off-by-one error in _sasl_add_string in common.c in cyrus-sasl.

Frequently asked questions

What is CVE-2019-19906?

cyrus-sasl (aka Cyrus SASL) 2.1.27 has an out-of-bounds write leading to unauthenticated remote denial-of-service in OpenLDAP via a malformed LDAP packet. The OpenLDAP crash is ultimately caused by an off-by-one error in _sasl_add_string in common.c in cyrus-sasl.

How severe is CVE-2019-19906?

CVE-2019-19906 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2019-19906 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 8% (94th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2019-19906?

CVE-2019-19906 primarily affects Cyrusimap Cyrus-sasl. In total, 52 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2019-19906?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2019-19906 published?

CVE-2019-19906 was published on 2019-12-19 and last updated on 2026-06-17.

References

• http://seclists.org/fulldisclosure/2020/Jul/23
• http://seclists.org/fulldisclosure/2020/Jul/24
• http://www.openwall.com/lists/oss-security/2022/02/23/4
• https://github.com/cyrusimap/cyrus-sasl/issues/587
• https://lists.apache.org/thread.html/r58af02e294bd07f487e2c64ffc0a29b837db5600e33b6e698b9d696b%40%3Cissues.bookkeeper.apache.org%3E
• https://lists.apache.org/thread.html/rf4c02775860db415b4955778a131c2795223f61cb8c6a450893651e4%40%3Cissues.bookkeeper.apache.org%3E
• https://lists.debian.org/debian-lts-announce/2019/12/msg00027.html
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/MW6GZCLECGL2PBNHVNPJIX4RPVRVFR7R/
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/OB4GSVOJ6ESHQNT5GSV63OX5D4KPSTGT/
• https://seclists.org/bugtraq/2019/Dec/42
• https://support.apple.com/kb/HT211288
• https://support.apple.com/kb/HT211289
• https://usn.ubuntu.com/4256-1/
• https://www.debian.org/security/2019/dsa-4591
• https://www.openldap.org/its/index.cgi/Incoming?id=9123

Affected products (52)

• cpe:2.3:a:cyrusimap:cyrus-sasl:*:*:*:*:*:*:*:*
• cpe:2.3:o:debian:debian_linux:8.0:*:*:*:*:*:*:*
• cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*
• cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*
• cpe:2.3:o:canonical:ubuntu_linux:12.04:*:*:*:-:*:*:*
• cpe:2.3:o:canonical:ubuntu_linux:14.04:*:*:*:esm:*:*:*
• cpe:2.3:o:canonical:ubuntu_linux:16.04:*:*:*:esm:*:*:*
• cpe:2.3:o:canonical:ubuntu_linux:18.04:*:*:*:lts:*:*:*
• cpe:2.3:o:canonical:ubuntu_linux:19.10:*:*:*:*:*:*:*
• cpe:2.3:o:fedoraproject:fedora:31:*:*:*:*:*:*:*
• cpe:2.3:o:fedoraproject:fedora:32:*:*:*:*:*:*:*
• cpe:2.3:a:redhat:jboss_enterprise_web_server:2.0.0:*:*:*:*:*:*:*
• cpe:2.3:o:apple:mac_os_x:10.14.6:-:*:*:*:*:*:*
• cpe:2.3:o:redhat:enterprise_linux:5.0:*:*:*:*:*:*:*
• cpe:2.3:o:redhat:enterprise_linux:6.0:*:*:*:*:*:*:*
• cpe:2.3:o:redhat:enterprise_linux:7.0:*:*:*:*:*:*:*
• cpe:2.3:o:redhat:enterprise_linux:8.0:*:*:*:*:*:*:*
• cpe:2.3:o:redhat:enterprise_linux_eus:8.4:*:*:*:*:*:*:*
• cpe:2.3:o:redhat:enterprise_linux_for_ibm_z_systems:8.0:*:*:*:*:*:*:*
• cpe:2.3:o:redhat:enterprise_linux_for_ibm_z_systems_eus:8.4:*:*:*:*:*:*:*
• cpe:2.3:o:redhat:enterprise_linux_for_power_little_endian:8.0:*:*:*:*:*:*:*
• cpe:2.3:o:redhat:enterprise_linux_for_power_little_endian_eus:8.4:*:*:*:*:*:*:*
• cpe:2.3:o:redhat:enterprise_linux_server_aus:8.4:*:*:*:*:*:*:*
• cpe:2.3:o:redhat:enterprise_linux_server_for_power_little_endian_update_services_for_sap_solutions:8.4:*:*:*:*:*:*:*
• cpe:2.3:o:redhat:enterprise_linux_server_tus:8.4:*:*:*:*:*:*:*
• cpe:2.3:o:redhat:enterprise_linux_server_update_services_for_sap_solutions:8.4:*:*:*:*:*:*:*
• cpe:2.3:o:apple:ipados:13.6:*:*:*:*:*:*:*
• cpe:2.3:o:apple:iphone_os:13.6:*:*:*:*:*:*:*
• cpe:2.3:o:apple:mac_os_x:*:*:*:*:*:*:*:*
• cpe:2.3:o:apple:mac_os_x:10.13.6:-:*:*:*:*:*:*
• cpe:2.3:o:apple:mac_os_x:10.13.6:security_update_2018-002:*:*:*:*:*:*
• cpe:2.3:o:apple:mac_os_x:10.13.6:security_update_2018-003:*:*:*:*:*:*
• cpe:2.3:o:apple:mac_os_x:10.13.6:security_update_2019-001:*:*:*:*:*:*
• cpe:2.3:o:apple:mac_os_x:10.13.6:security_update_2019-002:*:*:*:*:*:*
• cpe:2.3:o:apple:mac_os_x:10.13.6:security_update_2019-003:*:*:*:*:*:*
• cpe:2.3:o:apple:mac_os_x:10.13.6:security_update_2019-004:*:*:*:*:*:*
• cpe:2.3:o:apple:mac_os_x:10.13.6:security_update_2019-005:*:*:*:*:*:*
• cpe:2.3:o:apple:mac_os_x:10.13.6:security_update_2019-006:*:*:*:*:*:*
• cpe:2.3:o:apple:mac_os_x:10.13.6:security_update_2019-007:*:*:*:*:*:*
• cpe:2.3:o:apple:mac_os_x:10.13.6:security_update_2020-001:*:*:*:*:*:*

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