mirror of
https://github.com/postgres/postgres.git
synced 2025-04-24 10:47:04 +03:00
abf23ee86d
attacks where an attacker would put <attack>\0<propername> in the field and trick the validation code that the certificate was for <attack>. This is a very low risk attack since it reuqires the attacker to trick the CA into issuing a certificate with an incorrect field, and the common PostgreSQL deployments are with private CAs, and not external ones. Also, default mode in 8.4 does not do any name validation, and is thus also not vulnerable - but the higher security modes are. Backpatch all the way. Even though versions 8.3.x and before didn't have certificate name validation support, they still exposed this field for the user to perform the validation in the application code, and there is no way to detect this problem through that API. Security: CVE-2009-4034
$PostgreSQL: pgsql/src/backend/libpq/README.SSL,v 1.7 2008/10/24 11:48:29 mha Exp $
SSL
===
>From the servers perspective:
Receives StartupPacket
|
|
(Is SSL_NEGOTIATE_CODE?) ----------- Normal startup
| No
|
| Yes
|
|
(Server compiled with USE_SSL?) ------- Send 'N'
| No |
| |
| Yes Normal startup
|
|
Send 'S'
|
|
Establish SSL
|
|
Normal startup
>From the clients perspective (v6.6 client _with_ SSL):
Connect
|
|
Send packet with SSL_NEGOTIATE_CODE
|
|
Receive single char ------- 'S' -------- Establish SSL
| |
| '<else>' |
| Normal startup
|
|
Is it 'E' for error ------------------- Retry connection
| Yes without SSL
| No
|
Is it 'N' for normal ------------------- Normal startup
| Yes
|
Fail with unknown
---------------------------------------------------------------------------