Bug 2485421 (CVE-2026-11790)
| Summary: | CVE-2026-11790 389-ds-base: 389-ds-base: PBKDF2 password storage plugin unbounded iteration count denial of service | ||
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| Product: | [Other] Security Response | Reporter: | OSIDB Bzimport <bzimport> |
| Component: | vulnerability | Assignee: | Product Security DevOps Team <prodsec-dev> |
| Status: | NEW --- | QA Contact: | |
| Severity: | medium | Docs Contact: | |
| Priority: | medium | ||
| Version: | unspecified | CC: | aadhikar, bsmejkal, jachapma, mreynolds, progier, rhel-process-autobot, snegrini, spichugi, tbordaz, vashirov, watson-tool-maintainers |
| Target Milestone: | --- | Keywords: | Security |
| Target Release: | --- | ||
| Hardware: | All | ||
| OS: | Linux | ||
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| Fixed In Version: | Doc Type: | --- | |
| Doc Text: |
A flaw was found in 389 Directory Server. The PBKDF2-SHA256 password storage plugin does not enforce an upper bound on the iteration count extracted from stored password hashes. A privileged attacker who can modify a user's password hash can cause excessive CPU consumption during authentication, resulting in denial of service.
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Story Points: | --- |
| Clone Of: | Environment: | ||
| Last Closed: | Type: | --- | |
| Regression: | --- | Mount Type: | --- |
| Documentation: | --- | CRM: | |
| Verified Versions: | Category: | --- | |
| oVirt Team: | --- | RHEL 7.3 requirements from Atomic Host: | |
| Cloudforms Team: | --- | Target Upstream Version: | |
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The PBKDF2-SHA256 password storage plugin in 389 Directory Server extracts the iteration count from stored password hashes without an upper bound check. An attacker with Directory Manager privileges can plant a crafted {PBKDF2_SHA256} hash with extreme iteration counts (e.g. 0x7FFFFFFF). Any subsequent LDAP BIND as the poisoned account triggers unbounded CPU consumption, hanging a worker thread for hours and enabling persistent denial of service. Both the C plugin (pbkdf2_pwd.c) and Rust plugin (pwdchan/lib.rs) are affected. Distinct from CVE-2024-5953 which added hash length check but not iteration cap. Introduced in 389-ds-base 1.3.6 (commit 542287ce7, Ticket 397). PoC confirmed on Fedora 42 production binary.