ZABBIX BUGS AND ISSUES

Possible security issue due to misuse of the libcurl API

Details

Description

Alessandro Ghedini on behalf of Debian security team kindly shared his concerns regarding the following:

We recently discovered that zabbix is using the libcurl API in a way that may not be what the original author intended.
In particular I'm referring to the fact that the CURLOPT_SSL_VERIFYHOST option is treated as it was a boolean value
while in fact it isn't (it may take three different values):

From the file "src/libs/zbxmedia/eztexting.c":

    if (CURLE_OK != (err = curl_easy_setopt(easy_handle, opt = CURLOPT_USERAGENT, "Zabbix " ZABBIX_VERSION)) ||
                 CURLE_OK != (err = curl_easy_setopt(easy_handle, opt = CURLOPT_FOLLOWLOCATION, 1L)) ||
                 CURLE_OK != (err = curl_easy_setopt(easy_handle, opt = CURLOPT_WRITEFUNCTION, WRITEFUNCTION2)) ||
                 CURLE_OK != (err = curl_easy_setopt(easy_handle, opt = CURLOPT_HEADERFUNCTION, HEADERFUNCTION2)) ||
                 CURLE_OK != (err = curl_easy_setopt(easy_handle, opt = CURLOPT_SSL_VERIFYPEER, 1L)) ||
                 CURLE_OK != (err = curl_easy_setopt(easy_handle, opt = CURLOPT_SSL_VERIFYHOST, 1L)) ||
                 CURLE_OK != (err = curl_easy_setopt(easy_handle, opt = CURLOPT_POSTFIELDS, postfields)) ||
                 CURLE_OK != (err = curl_easy_setopt(easy_handle, opt = CURLOPT_POST, 1L)) ||
                 CURLE_OK != (err = curl_easy_setopt(easy_handle, opt = CURLOPT_URL, EZ_TEXTING_API_URL)) ||
                 CURLE_OK != (err = curl_easy_setopt(easy_handle, opt = CURLOPT_TIMEOUT, (long)EZ_TEXTING_TIMEOUT)))
    {
         zbx_snprintf(error, max_error_len, "Could not set cURL option %d: [%s]", opt, curl_easy_strerror(err));
         goto clean;
    }


Setting the value to "1" does not enable the host checks (well, not all of them)
and this may lead to security issues. The correct value to enable all the security checks is "2".

From the libcurl documentation:

> When CURLOPT_SSL_VERIFYHOST is 2, that certificate must indicate
> that the server is the server to which you meant to connect, or the
> connection fails.
>
> Curl considers the server the intended one when the Common Name
> field or a Subject Alternate Name field in the certificate matches
> the host name in the URL to which you told Curl to connect.
>
> When the value is 1, the certificate must contain a Common Name
> field, but it doesn't matter what name it says. (This is not
> ordinarily a useful setting).
>
> When the value is 0, the connection succeeds regardless of the
> names in the certificate.

Note that this should be fixed anyway, since as of curl v7.28.1 the value "1" is not a valid value
anymore and libcurl will return an error.

Activity

Hide
Henri Salo added a comment -
Show
Henri Salo added a comment - Please use CVE-2012-6086 for this issue. CVE request http://www.openwall.com/lists/oss-security/2013/01/02/1 CVE assigment http://www.openwall.com/lists/oss-security/2013/01/03/1
Hide
Matthew Marlowe added a comment -

As the gentoo package maintainer for Zabbix, I'd like to mention that this issue has reached the attention of our security team, and that curl 7.28.1 is currently one of the releases available to our users....if this bug isn't addressed shortly, I'll need to update our package to indicate it is not compatible with newer versions of curl.

Show
Matthew Marlowe added a comment - As the gentoo package maintainer for Zabbix, I'd like to mention that this issue has reached the attention of our security team, and that curl 7.28.1 is currently one of the releases available to our users....if this bug isn't addressed shortly, I'll need to update our package to indicate it is not compatible with newer versions of curl.
Hide
Volker Fröhlich added a comment -

Please take the time to address this 5 month old CVE!

Show
Volker Fröhlich added a comment - Please take the time to address this 5 month old CVE!
Hide
Matthew Marlowe added a comment -

curl 7.29 has now gone stable in gentoo although prior versions are still supported, please resolve this bug....thanks.

Show
Matthew Marlowe added a comment - curl 7.29 has now gone stable in gentoo although prior versions are still supported, please resolve this bug....thanks.
Hide
Andris Zeila added a comment -

Fixed in development branch svn://svn.zabbix.com/branches/dev/ZBX-5924

Show
Andris Zeila added a comment - Fixed in development branch svn://svn.zabbix.com/branches/dev/ZBX-5924
Hide
Volker Fröhlich added a comment - - edited

Backported to EPEL 5 and 6 zabbix20 packages, as well as zabbix 2.0 packages in Fedora.

1.8 in EPEL 6 remains to be done.

Show
Volker Fröhlich added a comment - - edited Backported to EPEL 5 and 6 zabbix20 packages, as well as zabbix 2.0 packages in Fedora. 1.8 in EPEL 6 remains to be done.
Hide
Alexander Vladishev added a comment -

Successfully tested!

Show
Alexander Vladishev added a comment - Successfully tested!
Hide
Andris Zeila added a comment -

Released in:
pre-1.8.18rc1 r37454
pre-2.0.8rc1 r37455
pre-2.1.2 r37456

Show
Andris Zeila added a comment - Released in: pre-1.8.18rc1 r37454 pre-2.0.8rc1 r37455 pre-2.1.2 r37456
Hide
Volker Fröhlich added a comment -

Backported to 1.8 in EPEL 6 (1.8.17-2)

Show
Volker Fröhlich added a comment - Backported to 1.8 in EPEL 6 (1.8.17-2)
Hide
richlv added a comment - - edited

subissue (1) has not been closed

Oleksiy Zagorskyi Closed already.

Show
richlv added a comment - - edited subissue (1) has not been closed Oleksiy Zagorskyi Closed already.

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Dates

  • Created:
    Updated:
    Resolved: