OpenPKG CVS Repository
http://cvs.openpkg.org/
____________________________________________________________________________
Server: cvs.openpkg.org Name: Ralf S. Engelschall
Root: /e/openpkg/cvs Email: [EMAIL PROTECTED]
Module: openpkg-web Date: 19-Feb-2003 15:58:40
Branch: HEAD Handle: 2003021914584000
Modified files:
openpkg-web/security OpenPKG-SA-2003.013-openssl.txt
Log:
more details I know of
Summary:
Revision Changes Path
1.4 +27 -8 openpkg-web/security/OpenPKG-SA-2003.013-openssl.txt
____________________________________________________________________________
patch -p0 <<'@@ .'
Index: openpkg-web/security/OpenPKG-SA-2003.013-openssl.txt
============================================================================
$ cvs diff -u -r1.3 -r1.4 OpenPKG-SA-2003.013-openssl.txt
--- openpkg-web/security/OpenPKG-SA-2003.013-openssl.txt 19 Feb 2003 14:40:01
-0000 1.3
+++ openpkg-web/security/OpenPKG-SA-2003.013-openssl.txt 19 Feb 2003 14:58:40
-0000 1.4
@@ -7,7 +7,7 @@
________________________________________________________________________
Package: openssl
-Vulnerability: timing attack on CBC
+Vulnerability: obtain plaintext of SSL/TLS communication
OpenPKG Specific: no
Affected Releases: Affected Packages: Corrected Packages:
@@ -21,11 +21,30 @@
OpenPKG 1.1 ??
Description:
- According to a OpenSSL security advisory [0] based on work from Serge
- Vaudenay, a crazy vulnerability exists in the
- ... [1] ....
- The Common Vulnerabilities and Exposures (CVE) project
- assigned the id CAN-2003-0078 [2] to the problem.
+ In an upcoming CRYPTO 2003 paper, Brice Canvel (EPFL), Alain Hiltgen
+ (UBS), Serge Vaudenay (EPFL), and Martin Vuagnoux (EPFL, Ilion)
+ describe and demonstrate a timing-based attack on CBC ciphersuites
+ in SSL and TLS. According to an OpenSSL security advisory [0],
+ the OpenSSL implementation is vulnerable to this attack. The
+ Common Vulnerabilities and Exposures (CVE) project assigned the id
+ CAN-2003-0078 [2] to the problem.
+
+ The attack assumes that multiple SSL or TLS connections involve a
+ common fixed plaintext block, such as a password. An active attacker
+ can substitute specifically made-up ciphertext blocks for blocks sent
+ by legitimate SSL/TLS parties and measure the time until a response
+ arrives: SSL/TLS includes data authentication to ensure that such
+ modified ciphertext blocks will be rejected by the peer (and the
+ connection aborted), but the attacker may be able to use timing
+ observations to distinguish between two different error cases, namely
+ block cipher padding errors and MAC verification errors. This is
+ sufficient for an adaptive attack that finally can obtain the complete
+ plaintext block.
+
+ OpenSSL version since 0.9.6c supposedly treat block cipher padding
+ errors like MAC verification errors during record decryption [1], but
+ MAC verification was still skipped after detection of a padding error,
+ which allowed the timing attack.
Please check whether you are affected by running "<prefix>/bin/rpm
-q openssl". If you have the "foo" package installed and its version
@@ -57,8 +76,8 @@
________________________________________________________________________
References:
- [0] http://www.example.com/bugfinder.html
- [1] http://www.foo.org/
+ [0] http://www.openssl.org/news/secadv_20030219.txt
+ [1] http://www.openssl.org/~bodo/tls-cbc.txt
[2] http://cve.mitre.org/cgi-bin/cvename.cgi?name=CAN-2003-0078
[3] http://www.openpkg.org/tutorial.html#regular-source
[4] http://www.openpkg.org/tutorial.html#regular-binary
@@ .
______________________________________________________________________
The OpenPKG Project www.openpkg.org
CVS Repository Commit List [EMAIL PROTECTED]
