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TITLE:
OpenSSL CRL Bypass and ECDH Denial of Service Vulnerability

SECUNIA ADVISORY ID:
SA45781

VERIFY ADVISORY:
Secunia.com
http://secunia.com/advisories/45781/
Customer Area (Credentials Required)
https://ca.secunia.com/?page=viewadvisory&vuln_id=45781

RELEASE DATE:
2011-09-06

DISCUSS ADVISORY:
http://secunia.com/advisories/45781/#comments

AVAILABLE ON SITE AND IN CUSTOMER AREA:
 * Last Update
 * Popularity
 * Comments
 * Criticality Level
 * Impact
 * Where
 * Solution Status
 * Operating System / Software
 * CVE Reference(s)

http://secunia.com/advisories/45781/

ONLY AVAILABLE IN CUSTOMER AREA:
 * Authentication Level
 * Report Reliability
 * Secunia PoC
 * Secunia Analysis
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 * Approve Distribution
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https://ca.secunia.com/?page=viewadvisory&vuln_id=45781

ONLY AVAILABLE WITH SECUNIA CSI AND SECUNIA PSI:
 * AUTOMATED SCANNING

http://secunia.com/vulnerability_scanning/personal/
http://secunia.com/vulnerability_scanning/corporate/wsus_sccm_3rd_third_party_patching/

DESCRIPTION:
Two vulnerabilities have been reported in OpenSSL, which can be
exploited by malicious people to bypass certain security restrictions
and cause a DoS (Denial of Service).

1) An error within OpenSSL's internal certificate verification can
lead to OpenSSL accepting CRL (Certificate Revocation Lists) with a
"nextUpdate" field set to a date in the past.

2) An error within the implementation of ephemeral ECDH ciphersuites
can be exploited to crash a vulnerable server by sending handshake
messages within an invalid order.

Successful exploitation of this vulnerability requires that the
server enabled and supports the ECDH ciphersuites.

NOTE: Additionally, the ECDH implementation is not thread safe.

The vulnerabilities are reported in versions 1.0.0 through 1.0.0d.

SOLUTION:
Update to version 1.0.0e.

PROVIDED AND/OR DISCOVERED BY:
The vendor credits:
1) Kaspar Brand
2) Adam Langley

ORIGINAL ADVISORY:
http://www.openssl.org/news/secadv_20110906.txt

OTHER REFERENCES:
Further details available in Customer Area:
http://secunia.com/vulnerability_intelligence/

DEEP LINKS:
Further details available in Customer Area:
http://secunia.com/vulnerability_intelligence/

EXTENDED DESCRIPTION:
Further details available in Customer Area:
http://secunia.com/vulnerability_intelligence/

EXTENDED SOLUTION:
Further details available in Customer Area:
http://secunia.com/vulnerability_intelligence/

EXPLOIT:
Further details available in Customer Area:
http://secunia.com/vulnerability_intelligence/

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About:
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