389-ds-base: 389-ds-base: heap buffer overflow in sasl_io_recv() via padded sasl unbind

Summary

A heap buffer overflow flaw was found in the SASL I/O layer of 389 Directory Server (389-ds-base). After a successful SASL bind with integrity protection (SSF > 0), an authenticated attacker can send a specially crafted oversized LDAP UNBIND packet that is copied into a 512-byte heap receive buffer without a bounds check in sasl_io_recv() in sasl_io.c. This allows up to approximately 2 megabytes of attacker-controlled data to overflow the buffer, causing a denial of service (server crash). In FreeIPA and Red Hat Identity Management deployments, any domain user with a valid Kerberos ticket, any enrolled host, or any service account can trigger this vulnerability over the network after authenticating via GSSAPI. The vulnerable code path has existed since approximately 2013 (389-ds-base 1.3.2) and was not addressed by the CVE-2025-14905 fix, which patched a separate heap overflow in schema.c only.

Timeline

1. Jul 7, 2026, 9:17 AM UTCCVE published
2. Jul 8, 2026, 9:02 PM UTCCISA SSVC assessment

   Exploitation: none · Automatable: no · Technical impact: total

3. Jul 8, 2026, 9:02 PM UTCRecord last updated

Affected versions

• 389-ds-base

  From 1.3.2 · through 3.3.0

• redhat-ds:11

  Version range not reported

• redhat-ds:11

  Version range not reported

• redhat-ds:11

  Version range not reported

• redhat-ds:12

  Version range not reported

• redhat-ds:12

  Version range not reported

• 389-ds-base

  Version range not reported

• 389-ds-base

  Version range not reported

• 389-ds-base

  Version range not reported

• 389-ds:1.4

  Version range not reported

• 389-ds:1.4

  Version range not reported

• 389-ds:1.4

  Version range not reported

• 389-ds:1.4

  Version range not reported

• 389-ds:1.4

  Version range not reported

• 389-ds:1.4

  Version range not reported

• 389-ds:1.4

  Version range not reported

• 389-ds-base

  Version range not reported

• 389-ds-base

  Version range not reported

• 389-ds-base

  Version range not reported

• 389-ds-base

  Version range not reported

• dirsrv/dirsrv-container-rhel10

  Version range not reported

• redhat-ds:12/389-ds-base

  Version range not reported

• 389-ds-base

  Version range not reported

• 389-ds-base

  Version range not reported

References 19