Bug 470079 (CVE-2008-4989)
| Summary: | CVE-2008-4989 gnutls: certificate chain verification flaw | ||||||
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| Product: | [Other] Security Response | Reporter: | Tomas Hoger <thoger> | ||||
| Component: | vulnerability | Assignee: | Red Hat Product Security <security-response-team> | ||||
| Status: | CLOSED ERRATA | QA Contact: | |||||
| Severity: | medium | Docs Contact: | |||||
| Priority: | medium | ||||||
| Version: | unspecified | CC: | kreilly, tmraz | ||||
| Target Milestone: | --- | Keywords: | Security | ||||
| Target Release: | --- | ||||||
| Hardware: | All | ||||||
| OS: | Linux | ||||||
| Whiteboard: | |||||||
| Fixed In Version: | Doc Type: | Bug Fix | |||||
| Doc Text: | Story Points: | --- | |||||
| Clone Of: | Environment: | ||||||
| Last Closed: | 2008-11-13 15:35:44 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: | 470279, 470280, 805160 | ||||||
| Bug Blocks: | |||||||
| Attachments: |
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Description
Tomas Hoger
2008-11-05 17:19:35 UTC
The problem seems to have been introduced in following commit: http://repo.or.cz/w/gnutls.git?a=commitdiff;h=c154545b8a3df4f7d06c6aa335c18740cbecf57a which first appeared in GnuTLS 1.2.4 released in May 2005: http://lists.gnupg.org/pipermail/gnutls-dev/2005-May/000875.html Update on the flaw description in comment #0: This issue does not require any crafted self-signed certificate to be listed in the certificate chain. The verification code in the vulnerable versions works as: - check last certificate in the chain against trusted CA certs - if last certificate in the chain is self-signed, it is dropped / ignored - verify possibly shorter certificate chain It is sufficient for server to provide chain with fake certificate followed by a trusted CA certificate to be successfully verified. Created attachment 322723 [details]
Proposed patch from the reporter of the issue that upstream plans to use
Public now via: http://article.gmane.org/gmane.comp.encryption.gpg.gnutls.devel/3215 http://www.gnu.org/software/gnutls/security.html Fixed upstream in: 2.6.1 Original report from Martin von Gagern: http://article.gmane.org/gmane.comp.encryption.gpg.gnutls.devel/3217 Original patch contained a bug, different version was proposed: http://article.gmane.org/gmane.comp.encryption.gpg.gnutls.devel/3224 (only drop last self-signed certificate when chain contains more than once certificate) The gnutls packages as shipped in Red Hat Enterprise Linux 4 were not affected by this flaw. gnutls-2.4.2-3.fc10 has been submitted as an update for Fedora 10. http://admin.fedoraproject.org/updates/gnutls-2.4.2-3.fc10 gnutls-2.0.4-4.fc9 has been submitted as an update for Fedora 9. http://admin.fedoraproject.org/updates/gnutls-2.0.4-4.fc9 gnutls-1.6.3-5.fc8 has been submitted as an update for Fedora 8. http://admin.fedoraproject.org/updates/gnutls-1.6.3-5.fc8 gnutls-2.0.4-4.fc9 has been pushed to the Fedora 9 stable repository. If problems still persist, please make note of it in this bug report. gnutls-1.6.3-5.fc8 has been pushed to the Fedora 8 stable repository. If problems still persist, please make note of it in this bug report. This issue was addressed in: Red Hat Enterprise Linux: http://rhn.redhat.com/errata/RHSA-2008-0982.html Fedora: https://admin.fedoraproject.org/updates/F8/FEDORA-2008-9600 https://admin.fedoraproject.org/updates/F9/FEDORA-2008-9530 gnutls-2.4.2-3.fc10 has been pushed to the Fedora 10 stable repository. If problems still persist, please make note of it in this bug report. |