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  1. Mar 01, 2016
  2. Feb 29, 2016
    • Matt Caswell's avatar
      Fix BN_hex2bn/BN_dec2bn NULL ptr/heap corruption · c1753084
      Matt Caswell authored
      
      
      In the BN_hex2bn function the number of hex digits is calculated using
      an int value |i|. Later |bn_expand| is called with a value of |i * 4|.
      For large values of |i| this can result in |bn_expand| not allocating any
      memory because |i * 4| is negative. This leaves ret->d as NULL leading
      to a subsequent NULL ptr deref. For very large values of |i|, the
      calculation |i * 4| could be a positive value smaller than |i|. In this
      case memory is allocated to ret->d, but it is insufficiently sized
      leading to heap corruption. A similar issue exists in BN_dec2bn.
      
      This could have security consequences if BN_hex2bn/BN_dec2bn is ever
      called by user applications with very large untrusted hex/dec data. This is
      anticipated to be a rare occurrence.
      
      All OpenSSL internal usage of this function uses data that is not expected
      to be untrusted, e.g. config file data or application command line
      arguments. If user developed applications generate config file data based
      on untrusted data then it is possible that this could also lead to security
      consequences. This is also anticipated to be a rare.
      
      Issue reported by Guido Vranken.
      
      CVE-2016-0797
      
      Reviewed-by: default avatarAndy Polyakov <appro@openssl.org>
      c1753084
  3. Feb 28, 2016
  4. Feb 27, 2016
  5. Feb 25, 2016
    • Matt Caswell's avatar
      Fix memory issues in BIO_*printf functions · 578b956f
      Matt Caswell authored
      
      
      The internal |fmtstr| function used in processing a "%s" format string
      in the BIO_*printf functions could overflow while calculating the length
      of a string and cause an OOB read when printing very long strings.
      
      Additionally the internal |doapr_outch| function can attempt to write to
      an OOB memory location (at an offset from the NULL pointer) in the event of
      a memory allocation failure. In 1.0.2 and below this could be caused where
      the size of a buffer to be allocated is greater than INT_MAX. E.g. this
      could be in processing a very long "%s" format string. Memory leaks can also
      occur.
      
      These issues will only occur on certain platforms where sizeof(size_t) >
      sizeof(int). E.g. many 64 bit systems. The first issue may mask the second
      issue dependent on compiler behaviour.
      
      These problems could enable attacks where large amounts of untrusted data
      is passed to the BIO_*printf functions. If applications use these functions
      in this way then they could be vulnerable. OpenSSL itself uses these
      functions when printing out human-readable dumps of ASN.1 data. Therefore
      applications that print this data could be vulnerable if the data is from
      untrusted sources. OpenSSL command line applications could also be
      vulnerable where they print out ASN.1 data, or if untrusted data is passed
      as command line arguments.
      
      Libssl is not considered directly vulnerable. Additionally certificates etc
      received via remote connections via libssl are also unlikely to be able to
      trigger these issues because of message size limits enforced within libssl.
      
      CVE-2016-0799
      
      Issue reported by Guido Vranken.
      
      Reviewed-by: default avatarAndy Polyakov <appro@openssl.org>
      578b956f
  6. Feb 24, 2016
    • Emilia Kasper's avatar
      CVE-2016-0798: avoid memory leak in SRP · 259b664f
      Emilia Kasper authored
      
      
      The SRP user database lookup method SRP_VBASE_get_by_user had confusing
      memory management semantics; the returned pointer was sometimes newly
      allocated, and sometimes owned by the callee. The calling code has no
      way of distinguishing these two cases.
      
      Specifically, SRP servers that configure a secret seed to hide valid
      login information are vulnerable to a memory leak: an attacker
      connecting with an invalid username can cause a memory leak of around
      300 bytes per connection.
      
      Servers that do not configure SRP, or configure SRP but do not configure
      a seed are not vulnerable.
      
      In Apache, the seed directive is known as SSLSRPUnknownUserSeed.
      
      To mitigate the memory leak, the seed handling in SRP_VBASE_get_by_user
      is now disabled even if the user has configured a seed.
      
      Applications are advised to migrate to SRP_VBASE_get1_by_user. However,
      note that OpenSSL makes no strong guarantees about the
      indistinguishability of valid and invalid logins. In particular,
      computations are currently not carried out in constant time.
      
      Reviewed-by: default avatarRich Salz <rsalz@openssl.org>
      259b664f
  7. Feb 23, 2016
  8. Feb 22, 2016
  9. Feb 19, 2016
  10. Feb 18, 2016
  11. Feb 16, 2016
  12. Feb 13, 2016
  13. Feb 12, 2016
  14. Feb 11, 2016
  15. Feb 10, 2016
  16. Feb 08, 2016
    • Matt Caswell's avatar
      Handle SSL_shutdown while in init more appropriately #2 · 64193c82
      Matt Caswell authored
      Previous commit f73c737c attempted to "fix" a problem with the way
      SSL_shutdown() behaved whilst in mid-handshake. The original behaviour had
      SSL_shutdown() return immediately having taken no action if called mid-
      handshake with a return value of 1 (meaning everything was shutdown
      successfully). In fact the shutdown has not been successful.
      
      Commit f73c737c
      
       changed that to send a close_notify anyway and then
      return. This seems to be causing some problems for some applications so
      perhaps a better (much simpler) approach is revert to the previous
      behaviour (no attempt at a shutdown), but return -1 (meaning the shutdown
      was not successful).
      
      This also fixes a bug where SSL_shutdown always returns 0 when shutdown
      *very* early in the handshake (i.e. we are still using SSLv23_method).
      
      Reviewed-by: default avatarViktor Dukhovni <viktor@openssl.org>
      64193c82
  17. Feb 06, 2016