Fix escaping in LDAP search strings [CVE-2020-14013] #239
Conversation
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
When username contains any special character (parentheses, asterisk, ...) user search will fail. When returned DN of user contains any escaped character (for example ",") group filter will fail. Example: (&(CN=group)(member=CN=dummy\, dummy2,OU=ou,DC=dc))" Which is wrong and doesn't work with Active directory. Correct is: (&(CN=group)(member=CN=dummy\5C, dummy2,OU=ou,DC=dc))" This patch fixies both of these bugs by using ldap_bv2escaped_filter_value from LDAP client to escape all of filter values. See: https://tools.ietf.org/search/rfc2254#page-5 Fix: kvspb#224 kvspb#180
onovy
changed the title
onovy
changed the title
Mic92
reviewed
Aug 19, 2020
| } | ||
|
|
||
| out.len = euserbv.bv_len; | ||
| out.data = ngx_pcalloc(r->pool, out.len); |
There was a problem hiding this comment.
Can ngx_pcalloc not fail?
Suggested change
| out.data = ngx_pcalloc(r->pool, out.len); | |
| out.data = ngx_pcalloc(r->pool, out.len); | |
| if (!out.data) { | |
| return out; | |
| } |
There was a problem hiding this comment.
returning out is not correct, because out.len will be set to new length but out.data will be null.
return ngx_null_string is probably better
There was a problem hiding this comment.
but tbh: Whole upstream code is not checking return code of ngx_pcalloc, so meh.
There was a problem hiding this comment.
Yeah. I saw that I will probably not use this module at all and use https://github.com/sto/ngx_http_auth_pam_module which seems much simpler and cleaner code.
|
I encountered the error during make install with this module. |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
When username contains any special character (parentheses, asterisk, ...)
user search will fail.
When returned DN of user contains any escaped character (for example ",")
group filter will fail.
Example:
Which is wrong and doesn't work with Active directory.
Correct is:
This patch fixies both of these bugs by using ldap_bv2escaped_filter_value
from LDAP client to escape all of filter values.
See: https://tools.ietf.org/search/rfc2254#page-5
Fixes #224 fixes #180
CVE-2020-14013