Bug 1983720 (CVE-2021-36222)
| Summary: | CVE-2021-36222 krb5: Sending a request containing PA-ENCRYPTED-CHALLENGE padata element without using FAST could result in NULL dereference in KDC which leads to DoS | ||
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| Product: | [Other] Security Response | Reporter: | Michael Kaplan <mkaplan> |
| Component: | vulnerability | Assignee: | Red Hat Product Security <security-response-team> |
| Status: | CLOSED ERRATA | QA Contact: | |
| Severity: | medium | Docs Contact: | |
| Priority: | medium | ||
| Version: | unspecified | CC: | abokovoy, asoldano, atangrin, bbaranow, bdettelb, bmaxwell, brian.stansberry, cdewolf, chazlett, csutherl, darran.lofthouse, dblechte, dfediuck, dkreling, dosoudil, dpal, eedri, eleandro, fcanogab, fdvorak, fjuma, gzaronik, iweiss, jclere, jochrist, jpallich, jperkins, j, jwon, krathod, kwills, lgao, mgoldboi, msochure, msvehla, mturk, nwallace, pjindal, pmackay, rguimara, rstancel, rsvoboda, sbose, sherold, smaestri, ssorce, szappis, tomckay, tom.jenkinson, yborgess, yturgema |
| Target Milestone: | --- | Keywords: | Security |
| Target Release: | --- | ||
| Hardware: | All | ||
| OS: | Linux | ||
| Whiteboard: | |||
| Fixed In Version: | krb5 1.19.2 | Doc Type: | If docs needed, set a value |
| Doc Text: |
A flaw was found in krb5. This flaw allows an unauthenticated attacker to cause a NULL dereference in the KDC by sending a request containing a PA-ENCRYPTED-CHALLENGE padata element without using FAST. The highest threat from this vulnerability is to system availability.
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Story Points: | --- |
| Clone Of: | Environment: | ||
| Last Closed: | 2021-09-21 12:26:21 UTC | Type: | --- |
| Regression: | --- | Mount Type: | --- |
| Documentation: | --- | CRM: | |
| Verified Versions: | Category: | --- | |
| oVirt Team: | --- | RHEL 7.3 requirements from Atomic Host: | |
| Cloudforms Team: | --- | Target Upstream Version: | |
| Embargoed: | |||
| Bug Depends On: | 1983728, 1983729, 1983733, 1992011 | ||
| Bug Blocks: | 1983721 | ||
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Description
Michael Kaplan
2021-07-19 15:27:58 UTC
Fixed in fedora: https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/thread/CCCYLGJLCVVNJVOQKUGKXR2SNQIPFBFS/ On ec_verify() function, when armor key is NULL it should return ENOENT, however due to a logic error the return value is overwritten by 0 in case k5memdup0() call is executed successfully before the check for armor key is executed. This leads to a NULL pointer dereference when further handling the armor key. An attacker may leverage this by sending crafted requests to KDC server, leading it to crash and causing a DoS. Created krb5 tracking bugs for this issue: Affects: fedora-all [bug 1992011] This issue has been addressed in the following products: Red Hat Enterprise Linux 8 Via RHSA-2021:3576 https://access.redhat.com/errata/RHSA-2021:3576 This bug is now closed. Further updates for individual products will be reflected on the CVE page(s): https://access.redhat.com/security/cve/cve-2021-36222 |