OpenSSL signature verification API misuses

[Till Ulen]

Binary package hint: openssl

Please see the details in the oCERT advisory #2008-016:
http://www.ocert.org/advisories/ocert-2008-016.html

"Several functions inside the OpenSSL library incorrectly check the result after calling the EVP_VerifyFinal function.

This bug allows a malformed signature to be treated as a good signature rather than as an error. This issue affects the signature checks on DSA and ECDSA keys used with SSL/TLS.

The flaw may be exploited by a malicious server or a man-in-the-middle attack that presents a malformed SSL/TLS signature from a certificate chain to a vulnerable client, bypassing validation."

This affects not only OpenSSL, but also Bind, NTP and some other packages.

[Jamie Strandboge (jdstrand)]

Thank you for using Ubuntu and taking the time to report a bug.

[Jamie Strandboge (jdstrand)]

openssl (0.9.8g-14ubuntu2) jaunty; urgency=low

  * SECURITY UPDATE: clients treat malformed signatures as good when verifying
    server DSA and ECDSA certificates
    - update apps/speed.c, apps/spkac.c, apps/verify.c, apps/x509.c,
      ssl/s2_clnt.c, ssl/s2_srvr.c, ssl/s3_clnt.c, s3_srvr.c, and
      ssl/ssltest.c to properly check the return code of EVP_VerifyFinal()
    - patch based on upstream patch for #2008-016
    - CVE-2008-5077

[Jamie Strandboge (jdstrand)]

OpenSSL issue is fixed in http://www.ubuntu.com/usn/usn-704-1.

[Jamie Strandboge (jdstrand)]

ntp (1:4.2.4p4+dfsg-7ubuntu3) jaunty; urgency=low

  * SECURITY UPDATE: clients treat malformed signatures as good when verifying
    server DSA and ECDSA certificates.
    - debian/patches/CVE-2009-0021.patch: update ntpd/ntp_crypto.c to properly
      check the return code of EVP_VerifyFinal()
    - CVE-2009-0021

[Jamie Strandboge (jdstrand)]

NTP issue is fixed in http://www.ubuntu.com/usn/usn-705-1.

[Jamie Strandboge (jdstrand)]

Bind9 is fixed in http://www.ubuntu.com/usn/usn-706-1.

[Jamie Strandboge (jdstrand)]

bind9 (1:9.5.0.dfsg.P2-5ubuntu1) jaunty; urgency=low

  * SECURITY UPDATE: clients treat malformed signatures as good when verifying
    server DSA and ECDSA certificates.
    - update lib/dns/openssldsa_link.c to properly check the return code of
      DSA_do_verify()
    - CVE-2009-0025

[Jamie Strandboge (jdstrand)]

openslp as of 1.2.1-5 (the one shipped in Dapper), doesn't build with --enable-security and in fact Build-Conflicts against libssl-dev (see http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=337606), so the package would need significant changes to be affected by this bug.