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Posted to commits@subversion.apache.org by st...@apache.org on 2021/02/10 13:32:38 UTC
svn commit: r1886385 - in /subversion/site/staging: news.html
security/CVE-2020-17525-advisory.txt
security/CVE-2020-17525-advisory.txt.asc security/index.html
Author: stsp
Date: Wed Feb 10 13:32:38 2021
New Revision: 1886385
URL: http://svn.apache.org/viewvc?rev=1886385&view=rev
Log:
Publish the CVE-202-17525 advisory in the staging/ area.
* staging/security/CVE-2020-17525-advisory.txt,
staging/security/CVE-2020-17525-advisory.txt.asc: Advisory.
* staging/news.html,
staging/security/index.html: Add news items.
Added:
subversion/site/staging/security/CVE-2020-17525-advisory.txt
subversion/site/staging/security/CVE-2020-17525-advisory.txt.asc
Modified:
subversion/site/staging/news.html
subversion/site/staging/security/index.html
Modified: subversion/site/staging/news.html
URL: http://svn.apache.org/viewvc/subversion/site/staging/news.html?rev=1886385&r1=1886384&r2=1886385&view=diff
==============================================================================
--- subversion/site/staging/news.html (original)
+++ subversion/site/staging/news.html Wed Feb 10 13:32:38 2021
@@ -22,6 +22,27 @@
<!-- Maybe we could insert H2's to split up the news items by -->
<!-- calendar year if we felt the need to do so. -->
+<div class="h3" id="news-20210210">
+<h3>2021-02-10 — Apache Subversion Security Advisory
+<a class="sectionlink" href="#news-20210210"
+ title="Link to this section">¶</a>
+</h3>
+
+<p>The recent releases of Apache Subversion 1.14.1 and 1.10.7 contain
+ a fix for a security issue: <a
+ href="/security/CVE-2020-17525-advisory.txt">CVE-2020-17525</a>. This issue
+ affect Subversion 'mod_dav_svn' servers only. We encourage server operators
+ to upgrade to the latest appropriate version as soon as reasonable.
+
+ Please see the <a
+ href="https://lists.apache.org/list.html?announce@subversion.apache.org"
+ >release announcements</a> for more information about the releases.</p>
+
+<p>To get the latest release from the nearest mirror, please visit our
+ <a href="/download.cgi">download page</a>.</p>
+
+</div> <!-- #news-20210210 -->
+
<div class="h3" id="news-20210210-1.14.1">
<h3>2021-02-10 — Apache Subversion 1.14.1 Released
<a class="sectionlink" href="#news-20210210-1.14.1"
Added: subversion/site/staging/security/CVE-2020-17525-advisory.txt
URL: http://svn.apache.org/viewvc/subversion/site/staging/security/CVE-2020-17525-advisory.txt?rev=1886385&view=auto
==============================================================================
--- subversion/site/staging/security/CVE-2020-17525-advisory.txt (added)
+++ subversion/site/staging/security/CVE-2020-17525-advisory.txt Wed Feb 10 13:32:38 2021
@@ -0,0 +1,114 @@
+
+ Remote unauthenticated denial-of-service in Subversion mod_authz_svn.
+
+Summary:
+========
+
+ Subversion's mod_authz_svn module will crash if the server is using
+ in-repository authz rules with the AuthzSVNReposRelativeAccessFile
+ option and a client sends a request for a non-existing repository URL.
+
+ This can lead to disruption for users of the service.
+
+Known vulnerable:
+=================
+
+ mod_dav_svn+mod_authz_svn servers 1.9.0 through 1.10.6 (inclusive).
+ mod_dav_svn+mod_authz_svn servers 1.11.0 through 1.14.0 (inclusive).
+
+Known fixed:
+============
+
+ mod_dav_svn+mod_authz_svn servers 1.14.1
+ mod_dav_svn+mod_authz_svn servers 1.10.7
+
+Details:
+========
+
+ A null-pointer-dereference has been found in mod_authz_svn that results in
+ a remote unauthenticated Denial-of-Service in some server configurations.
+
+ The vulnerability can be triggered by an unauthenticated user if the
+ Apache HTTPD server is configured to use an in-repository authz file,
+ with configuration directives such as:
+
+ AuthzSVNAccessFile "^/authz"
+ AuthzSVNReposRelativeAccessFile "^/authz"
+
+ The problem originates when sending a GET request to a non-existent
+ repository. The mod_authz_svn module will attempt to find authz rules
+ at a path within the requested SVN repository. Upon constructing this
+ path, the function svn_repos_find_root_path will return a NULL pointer
+ since the requested repository does not exist on-disk.
+ A check for this legitimate NULL pointer condition is missing, which
+ results in a segmentation fault when the NULL pointer is used.
+
+ The in-repository authz feature was first introduced in Subversion 1.8:
+ https://subversion.apache.org/docs/release-notes/1.8.html#in-repo-authz
+
+ The missing NULL check was first introduced during refactoring of the
+ authz code during development work leading up to Subversion 1.9.
+ Subversion 1.8 servers are unaffected.
+
+Severity:
+=========
+
+ CVSSv3 Base Score: 7.5 (High)
+
+ CVSSv3 Base Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
+
+ Exploitation results in denial of service by crashing the HTTPD worker
+ handling the request. The impact of this differs depending on how the
+ Apache HTTPD server is configured, including the choice of MPM (Multi-
+ Processing-Module). If the worker shares its memory address space with
+ the main thread, as is the case with e.g. the Event MPM, the entire
+ HTTPD server process will terminate. If the pre-fork MPM is used, the
+ worker will terminate but the HTTPD server will stay up, and service
+ availability will depend on how frequently the attacker is able to
+ send malicious requests which target the vulnerability.
+
+Recommendations:
+================
+
+ We recommend all users to upgrade to a known fixed release of the
+ Subversion mod_dav_svn server.
+
+ Users who are unable to upgrade may apply the included patches.
+
+ As a workaround, the use of in-repository authz rules files with
+ the AuthzSVNReposRelativeAccessFile can be avoided by switching
+ to an alternative configuration which fetches an authz rules file
+ from the server's filesystem, rather than from an SVN repository.
+
+References:
+===========
+
+ CVE-2020-17525 (Subversion)
+
+Reported by:
+============
+
+ Thomas Ã
kesson, simonsoft.se
+
+Patches:
+========
+
+ Patch for Subversion 1.10, 1.14:
+
+[[[
+Index: subversion/libsvn_repos/config_file.c
+===================================================================
+--- subversion/libsvn_repos/config_file.c (revision 1883994)
++++ subversion/libsvn_repos/config_file.c (working copy)
+@@ -237,6 +237,10 @@ get_repos_config(svn_stream_t **stream,
+ {
+ /* Search for a repository in the full path. */
+ repos_root_dirent = svn_repos_find_root_path(dirent, scratch_pool);
++ if (repos_root_dirent == NULL)
++ return svn_error_trace(handle_missing_file(stream, checksum, access,
++ url, must_exist,
++ svn_node_none));
+
+ /* Attempt to open a repository at repos_root_dirent. */
+ SVN_ERR(svn_repos_open3(&access->repos, repos_root_dirent, NULL,
+]]]
Added: subversion/site/staging/security/CVE-2020-17525-advisory.txt.asc
URL: http://svn.apache.org/viewvc/subversion/site/staging/security/CVE-2020-17525-advisory.txt.asc?rev=1886385&view=auto
==============================================================================
--- subversion/site/staging/security/CVE-2020-17525-advisory.txt.asc (added)
+++ subversion/site/staging/security/CVE-2020-17525-advisory.txt.asc Wed Feb 10 13:32:38 2021
@@ -0,0 +1,10 @@
+-----BEGIN PGP SIGNATURE-----
+
+iQEcBAABAgAGBQJgI9qaAAoJEE99uqmaWblzcKsIAJ3kHO5cTxr/mEwqc9Vc4XHK
+JFX9ttB8p0ZopdNFHyySKn/o7G+Y6slDTfea9/vIGXJVoYKjmct83XNNMkgPIiL9
++3jcrVO55EqrJtI6rwrapsJWn2D1Zw/ueDiEAHgk2VhgbDQ/barn+5k77pq8bUFc
+fYZoYxkVZU7yeZc5DjUS4PVq5jpA9OTB4AgivxXlP9vpkdS6Vz1Hf7MjI28pRD4h
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+PD8XDSulRhzB48Kzvb81zX1UzgLpNbgNpP+wruu9Ca46D3osjTG5df3h3uIypYw=
+=v3Nb
+-----END PGP SIGNATURE-----
Modified: subversion/site/staging/security/index.html
URL: http://svn.apache.org/viewvc/subversion/site/staging/security/index.html?rev=1886385&r1=1886384&r2=1886385&view=diff
==============================================================================
--- subversion/site/staging/security/index.html (original)
+++ subversion/site/staging/security/index.html Wed Feb 10 13:32:38 2021
@@ -306,6 +306,13 @@ clients using http(s)://</td>
<td>Remote unauthenticated denial-of-service in Subversion svnserve.</td>
</tr>
+<tr>
+<td><a href="CVE-2020-17525-advisory.txt">CVE-2020-17525-advisory.txt</a>
+[<a href="CVE-2020-17525-advisory.txt.asc">PGP</a>]</td>
+<td>1.9.0-1.9.10, 1.10.0-1.10.6, 1.11.0-1.11.1, 1.12.0-1.12.2, 1.13.0, 1.14.0</td>
+<td>Remote unauthenticated denial-of-service in mod_authz_svn.</td>
+</tr>
+
</tbody>
</table>