CVE-2021-27212
HighCVSS 7.5Exploitation Probability (EPSS)
Very high risk99th percentile - higher than 99% of all known CVEs
Summary
In OpenLDAP through 2.4.57 and 2.5.x through 2.5.1alpha, an assertion failure in slapd can occur in the issuerAndThisUpdateCheck function via a crafted packet, resulting in a denial of service (daemon exit) via a short timestamp. This is related to schema_init.c and checkTime.
Risk Assessment
An attacker can remotely cause a crash of the slapd directory service, resulting in denial of access to authentication and directory services. This may disrupt many applications that depend on OpenLDAP.
Recommendation
Update OpenLDAP to a version later than 2.4.57 or 2.5.1alpha that contains the fix. It is also recommended to monitor slapd service availability and implement mechanisms to restrict traffic from untrusted sources.
Other vulnerabilities in OpenLDAP
See all- CVE-2022-29155Critical
In OpenLDAP 2.x before 2.5.12 and 2.6.x before 2.6.2, there is a SQL injection vulnerability in the experimental back-sql backend to slapd, via a SQL statement within an LDAP query. This can occur during an LDAP search operation when the search filter is processed, due to a lack of proper escaping.
- CVE-2020-36230High
A flaw in OpenLDAP before 2.4.57 leads to an assertion failure in slapd during X.509 DN parsing in decode.c (ber_next_element), resulting in denial of service.
- CVE-2020-36229High
A flaw was discovered in OpenLDAP before 2.4.57 in ldap_X509dn2bv leading to a slapd crash in X.509 DN parsing in ad_keystring, resulting in denial of service.
- CVE-2020-36228High
An integer underflow was discovered in OpenLDAP before 2.4.57 leading to a slapd crash in the Certificate List Exact Assertion processing, resulting in denial of service.
- CVE-2020-36227High
A flaw was discovered in OpenLDAP before 2.4.57 leading to an infinite loop in slapd with the cancel_extop Cancel operation, resulting in denial of service.
- CVE-2020-36226High
A flaw was discovered in OpenLDAP before 2.4.57 leading to a memch->bv_len miscalculation and slapd crash in the saslAuthzTo processing, resulting in denial of service.
- CVE-2020-36225High
A flaw was discovered in OpenLDAP before 2.4.57 leading to a double free and slapd crash in the saslAuthzTo processing, resulting in denial of service.
- CVE-2020-36224High
A flaw was discovered in OpenLDAP before 2.4.57 leading to an invalid pointer free and slapd crash in the saslAuthzTo processing, resulting in denial of service.
- CVE-2020-36223High
A flaw was discovered in OpenLDAP before 2.4.57 leading to a slapd crash in the Values Return Filter control handling, resulting in denial of service (double free and out-of-bounds read).
- CVE-2020-36222High
A flaw was discovered in OpenLDAP before 2.4.57 leading to an assertion failure in slapd in the saslAuthzTo validation, resulting in denial of service.
Original NVD description (English source)
In OpenLDAP through 2.4.57 and 2.5.x through 2.5.1alpha, an assertion failure in slapd can occur in the issuerAndThisUpdateCheck function via a crafted packet, resulting in a denial of service (daemon exit) via a short timestamp. This is related to schema_init.c and checkTime.
Vulnerability data from NVD (NIST) · CISA KEV · EPSS