This email is a confidential pre-notification for security issues with Subversion: * CVE-2013-4505 * CVE-2013-4558 The public announcement is not until 25 November 2013 17:00 UTC, and we'd like to keep the information embargoed until the announcement. You are receiving this mail because (we think) you distribute software that uses the Subversion libraries or that you host a Subversion installation used by a large number of users. We believe that you might want to have your software patched by the time these security holes are made public on 25 November. If you no longer maintain Subversion-related packages or hosting, please reply to this mail indicating who the appropriate contact would be for your organization. Below are the advisories, followed by patches to fix the problems. The patches apply to Subversion 1.7.x and Subversion 1.8.x. Subversion 1.8.5 and Subversion 1.7.14 will be published on 25 November, including the patches below, as well as other stability and bug fixes. You can get an advance copy of the source distribution here: https://dist.apache.org/repos/dist/dev/subversion/ Here are the full advisories: {{{ mod_dontdothat does not restrict requests from serf based clients. Summary: ======== mod_dontdothat allows you to block update REPORT requests against certain paths in the repository. It expects the paths in the REPORT request to be absolute URLs. Serf based clients send relative URLs instead of absolute URLs in many cases. As a result these clients are not blocked as configured by mod_dontdothat. Known vulnerable: ================= mod_dontdothat 1.4.0 through 1.7.13 mod_dontdothat 1.8.0 through 1.8.4 Note that mod_dontdothat was in contrib until 1.7.3 and contrib is not included in Subversion source tarballs since 1.7.0, so Subversion 1.7.0 through 1.7.2 did not included mod_dontdothat (it was still available from the repository tags for those versions under contrib). Known fixed: ============ mod_dontdothat 1.7.14 mod_dontdothat 1.8.5 Details: ======== mod_dontdothat allows the blocking of certain update REPORT requests based on the paths of the requests. This is typically done to block requests against the root of the repository or the tags and branches directories where there may be large trees and require a large amount of server resources to fulfill. Update REPORT requests are used to fulfill requests from the client for the following commands: checkout update export diff (when a server URL or revision other than the BASE is specified) status -u copy $URL $WC The request body for the request includes a src-path and sometimes a dst-path entity. mod_dontdothat matches those paths against the configured paths to deny. When matching the src-path and dst-path, mod_dontdothat expects that an absolute URL will be provided. However, serf clients in the case of the src-path entity only provided a relative path. Relative paths have been supported by mod_dav_svn since before Subversion 1.0, but neon based clients never produced them. When a path is not an absolute URL then mod_dontdothat allowed the request. As a result a serf client was not blocked by mod_dontdothat. It's possible for other clients to be modified to avoid the restrictions as well, though we are unaware of anyone doing so. Severity: ========= CVSSv2 Base Score: 2.6 CVSSv2 Base Vector: AV:N/AC:H/Au:N/C:N/I:N/A:P We consider this to be a low risk vulnerability. mod_dontdothat is not typically installed. It is not intended or useful as an access control mechanism. Rather it exists primarily to prevent users unintentionally making expensive requests against the server. Clients may be able to use more resources than the server admin may have expected and planned for based on their configuration. This increased resource usage may impact performance and the availability of the server. A server admin who has configured mod_dontdothat would expect matching update REPORT requests to be blocked, but they will not be with serf based clients. Serf was added as a http library in Subversion 1.4 as a compile time option. In 1.5 it was possible to chose it at run time, provided it had been enabled at compile time. With 1.8 it became the only supported http library. As a result clients that can evade these restrictions are in common use and no special effort is required to do so. Recommendations: ================ Admins using mod_dontdothat are advised to upgrade to 1.7.14 or 1.8.5. It may be possible to configure http to disable all requests without an absolute URL in the update REPORT requests. However, doing so has the effect of disabling all serf based clients. Given that serf is the only http library for 1.8.x we do not recommend doing so. References: =========== CVE-2013-4505 (Subversion) Reported by: ============ Ben Reser, WANdisco Patches: ======== Patch for Subversion 1.7.x and 1.8.x: [[[ Index: tools/server-side/mod_dontdothat/mod_dontdothat.c =================================================================== --- tools/server-side/mod_dontdothat/mod_dontdothat.c (revision 1541183) +++ tools/server-side/mod_dontdothat/mod_dontdothat.c (working copy) @@ -30,6 +30,7 @@ #include <util_filter.h> #include <ap_config.h> #include <apr_strings.h> +#include <apr_uri.h> #include <expat.h> @@ -36,6 +37,8 @@ #include "mod_dav_svn.h" #include "svn_string.h" #include "svn_config.h" +#include "svn_path.h" +#include "private/svn_fspath.h" module AP_MODULE_DECLARE_DATA dontdothat_module; @@ -161,6 +164,34 @@ } } +/* duplicate of dav_svn__log_err() from mod_dav_svn/util.c */ +static void +log_dav_err(request_rec *r, + dav_error *err, + int level) +{ + dav_error *errscan; + + /* Log the errors */ + /* ### should have a directive to log the first or all */ + for (errscan = err; errscan != NULL; errscan = errscan->prev) { + apr_status_t status; + + if (errscan->desc == NULL) + continue; + +#if AP_MODULE_MAGIC_AT_LEAST(20091119,0) + status = errscan->aprerr; +#else + status = errscan->save_errno; +#endif + + ap_log_rerror(APLOG_MARK, level, status, r, + "%s [%d, #%d]", + errscan->desc, errscan->status, errscan->error_id); + } +} + static svn_boolean_t is_this_legal(dontdothat_filter_ctx *ctx, const char *uri) { @@ -167,20 +198,37 @@ const char *relative_path; const char *cleaned_uri; const char *repos_name; + const char *uri_path; int trailing_slash; dav_error *derr; - /* Ok, so we need to skip past the scheme, host, etc. */ - uri = ap_strstr_c(uri, "://"); - if (uri) - uri = ap_strchr_c(uri + 3, '/'); + /* uri can be an absolute uri or just a path, we only want the path to match + * against */ + if (uri && svn_path_is_url(uri)) + { + apr_uri_t parsed_uri; + apr_status_t rv = apr_uri_parse(ctx->r->pool, uri, &parsed_uri); + if (APR_SUCCESS != rv) + { + /* Error parsing the URI, log and reject request. */ + ap_log_rerror(APLOG_MARK, APLOG_ERR, rv, ctx->r, + "mod_dontdothat: blocked request after failing " + "to parse uri: '%s'", uri); + return FALSE; + } + uri_path = parsed_uri.path; + } + else + { + uri_path = uri; + } - if (uri) + if (uri_path) { const char *repos_path; derr = dav_svn_split_uri(ctx->r, - uri, + uri_path, ctx->cfg->base_path, &cleaned_uri, &trailing_slash, @@ -194,7 +242,7 @@ if (! repos_path) repos_path = ""; - repos_path = apr_psprintf(ctx->r->pool, "/%s", repos_path); + repos_path = svn_fspath__canonicalize(repos_path, ctx->r->pool); /* First check the special cases that are always legal... */ for (idx = 0; idx < ctx->allow_recursive_ops->nelts; ++idx) @@ -228,7 +276,20 @@ } } } + else + { + log_dav_err(ctx->r, derr, APLOG_ERR); + return FALSE; + } + } + else + { + ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, ctx->r, + "mod_dontdothat: empty uri passed to is_this_legal(), " + "module bug?"); + return FALSE; + } return TRUE; } ]]] }}} {{{ mod_dav_svn assertion triggered by non-canonical URLs in autoversioning commits. Summary: ======== When SVNAutoversioning is enabled via SVNAutoversioning on commits can be made by single HTTP requests such as MKCOL and PUT. If Subversion is built with assertions enabled any such requests that have non-canonical URLs, such as URLs with a trailing /, may trigger an assert. An assert will cause the Apache process to abort. Known vulnerable: ================= mod_dav_svn 1.7.0 through 1.7.13 mod_dav_svn 1.8.0 through 1.8.4 Known fixed: ============ mod_dav_svn 1.7.14 mod_dav_svn 1.8.5 Details: ======== Given a repository located at http://example.com/repos the assert can be triggered by commands like: curl -X PUT http://example.com/repos/A/ curl -X MKCOL http://example.com/repos/A/../B The assert happens after the commit has happened in the repository and will not occur if the commit is rejected. Severity: ========= CVSSv2 Base Score: 3.5 CVSSv2 Base Vector: AV:N/AC:M/Au:S/C:N/I:N/A:P We consider this to be a low risk vulnerability. The attacker needs to have commit access to the repository to exploit the vulnerability. Most Subversion servers do not have autoversioning enabled. In order for there to be any impact assertions must have been enabled when mod_dav_svn was built. In this case if assertions are disabled there is no impact. They are enabled by default on *nix and disabled on Windows. The assertion will cause the http server process to abort. Apache httpd servers using a prefork MPM will simply start a new process to replace the process that died. Servers using threaded MPMs may be processing other requests in the same process as the process that the attack causes to die. In either case there is an increased processing impact of restarting a process and the cost of per process caches being lost. Recommendations: ================ We recommend all users upgrade mod_dav_svn to Subversion 1.8.5 or 1.7.14 or newer. Disabling SVNAutoversioning will avoid the problem. Building Subversion with assertions disabled will avoid the problem. This can be done using the -disable-debug option to configure on *nix and by using a Release buld profile on Windows. References: =========== CVE-2013-4558 (Subversion) Reported by: ============ Philip Martin, WANdisco Patches: ======== Patch for Subversion 1.7.x and 1.8.x: [[[ Index: subversion/mod_dav_svn/repos.c =================================================================== --- subversion/mod_dav_svn/repos.c (revision 1539596) +++ subversion/mod_dav_svn/repos.c (working copy) @@ -2456,9 +2456,12 @@ get_parent_resource(const dav_resource *resource, parent->info = parentinfo; parentinfo->uri_path = - svn_stringbuf_create(get_parent_path(resource->info->uri_path->data, - TRUE, resource->pool), - resource->pool); + svn_stringbuf_create( + get_parent_path( + svn_urlpath__canonicalize(resource->info->uri_path->data, + resource->pool), + TRUE, resource->pool), + resource->pool); parentinfo->repos = resource->info->repos; parentinfo->root = resource->info->root; parentinfo->r = resource->info->r; ]]] }}}
SEMI-PUBLIC, as fix can be viewed in trunk
A small update to the advisory for CVE-2013-4558 that I sent out on 14 November 2013. The only thing that has changed is that the vulnerable versions has been reduced since the issue was created by the fix for CVE-2013-4131. Thanks to Murray McAllister of RedHat for asking some questions that lead to the discovery of this inaccuracy in our advisory. The embargo date for this remains 25 November 2013 17:00 UTC. The updated advisory follows: {{{ mod_dav_svn assertion triggered by non-canonical URLs in autoversioning commits. Summary: ======== When SVNAutoversioning is enabled via SVNAutoversioning on commits can be made by single HTTP requests such as MKCOL and PUT. If Subversion is built with assertions enabled any such requests that have non-canonical URLs, such as URLs with a trailing /, may trigger an assert. An assert will cause the Apache process to abort. Known vulnerable: ================= mod_dav_svn 1.7.11 through 1.7.13 mod_dav_svn 1.8.1 through 1.8.4 Known fixed: ============ mod_dav_svn 1.7.14 mod_dav_svn 1.8.5 Details: ======== Given a repository located at http://example.com/repos the assert can be triggered by commands like: curl -X PUT http://example.com/repos/A/ curl -X MKCOL http://example.com/repos/A/../B The assert happens after the commit has happened in the repository and will not occur if the commit is rejected. Severity: ========= CVSSv2 Base Score: 3.5 CVSSv2 Base Vector: AV:N/AC:M/Au:S/C:N/I:N/A:P We consider this to be a low risk vulnerability. The attacker needs to have commit access to the repository to exploit the vulnerability. Most Subversion servers do not have autoversioning enabled. In order for there to be any impact assertions must have been enabled when mod_dav_svn was built. In this case if assertions are disabled there is no impact. They are enabled by default on *nix and disabled on Windows. The assertion will cause the http server process to abort. Apache httpd servers using a prefork MPM will simply start a new process to replace the process that died. Servers using threaded MPMs may be processing other requests in the same process as the process that the attack causes to die. In either case there is an increased processing impact of restarting a process and the cost of per process caches being lost. Recommendations: ================ We recommend all users upgrade mod_dav_svn to Subversion 1.8.5 or 1.7.14 or newer. Disabling SVNAutoversioning will avoid the problem. Building Subversion with assertions disabled will avoid the problem. This can be done using the -disable-debug option to configure on *nix and by using a Release buld profile on Windows. References: =========== CVE-2013-4558 (Subversion) Reported by: ============ Philip Martin, WANdisco Patches: ======== Patch for Subversion 1.7.x and 1.8.x: [[[ Index: subversion/mod_dav_svn/repos.c =================================================================== --- subversion/mod_dav_svn/repos.c (revision 1539596) +++ subversion/mod_dav_svn/repos.c (working copy) @@ -2456,9 +2456,12 @@ get_parent_resource(const dav_resource *resource, parent->info = parentinfo; parentinfo->uri_path = - svn_stringbuf_create(get_parent_path(resource->info->uri_path->data, - TRUE, resource->pool), - resource->pool); + svn_stringbuf_create( + get_parent_path( + svn_urlpath__canonicalize(resource->info->uri_path->data, + resource->pool), + TRUE, resource->pool), + resource->pool); parentinfo->repos = resource->info->repos; parentinfo->root = resource->info->root; parentinfo->r = resource->info->r; ]]] }}}
This issue is now public @maintainers: please bump it in tree and say when it will be ready to stabilize, thanks
*** Bug 492626 has been marked as a duplicate of this bug. ***
version 1.7.14 added, will add arch teams for stabilizatin tomorrow, if no major regressions are reported till then
arches, please mark stable: =dev-vcs/subversion-1.7.14 target keywords="alpha amd64 arm hppa ia64 ~mips ppc ppc64 ~s390 ~sh sparc x86 ~ppc-aix ~amd64-fbsd ~x86-fbsd ~x86-freebsd ~hppa-hpux ~ia64-hpux ~x86-interix ~amd64-linux ~arm-linux ~x86-linux ~ppc-macos ~x64-macos ~x86-macos ~m68k-mint ~sparc-solaris ~sparc64-solaris ~x64-solaris ~x86-solaris"
Stable for HPPA.
amd64 stable
x86 stable
ppc stable
ppc64 stable
arm stable
alpha stable
CVE-2013-4558 (http://nvd.nist.gov/nvd.cfm?cvename=CVE-2013-4558): The get_parent_resource function in repos.c in mod_dav_svn Apache HTTPD server module in Subversion 1.7.11 through 1.7.13 and 1.8.1 through 1.8.4, when built with assertions enabled and SVNAutoversioning is enabled, allows remote attackers to cause a denial of service (assertion failure and Apache process abort) via a non-canonical URL in a request, as demonstrated using a trailing /. CVE-2013-4505 (http://nvd.nist.gov/nvd.cfm?cvename=CVE-2013-4505): The is_this_legal function in mod_dontdothat for Apache Subversion 1.4.0 through 1.7.13 and 1.8.0 through 1.8.4 allows remote attackers to bypass intended access restrictions and possibly cause a denial of service (resource consumption) via a relative URL in a REPORT request.
sparc stable
Ready for vote, I vote NO.
GLSA vote: no. Note to maintainers: please clean up after the last version is stabled.
still waiting for ia64 stabilization
ia64 stable
old version removed
closed as [noglsa]
