From 766ba72f56a9e4708c0df88fdff3b9ba68f62afd Mon Sep 17 00:00:00 2001 From: Lee Chee Yang Date: Tue, 11 May 2021 18:59:08 +0800 Subject: subversion: fix CVE-2020-17525 (From OE-Core rev: 3975fe2156d30cc64005e56666f4e88716d5ba27) Signed-off-by: Lee Chee Yang Signed-off-by: Steve Sakoman Signed-off-by: Richard Purdie --- .../subversion/subversion/CVE-2020-17525.patch | 117 +++++++++++++++++++++ .../subversion/subversion_1.13.0.bb | 1 + 2 files changed, 118 insertions(+) create mode 100644 meta/recipes-devtools/subversion/subversion/CVE-2020-17525.patch diff --git a/meta/recipes-devtools/subversion/subversion/CVE-2020-17525.patch b/meta/recipes-devtools/subversion/subversion/CVE-2020-17525.patch new file mode 100644 index 0000000000..5bebde2a86 --- /dev/null +++ b/meta/recipes-devtools/subversion/subversion/CVE-2020-17525.patch @@ -0,0 +1,117 @@ +Upstream-Status: Backport [ https://subversion.apache.org/security/CVE-2020-17525-advisory.txt ] +CVE: CVE-2020-17525 +Signed-off-by: Chee Yang Lee + + 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 Åkesson, simonsoft.se + +Patches: +======== + + Patch for Subversion 1.10, 1.14: + +[[[ +Index: subversion/libsvn_repos/config_file.c +=================================================================== +--- a/subversion/libsvn_repos/config_file.c (revision 1883994) ++++ b/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, +]]] diff --git a/meta/recipes-devtools/subversion/subversion_1.13.0.bb b/meta/recipes-devtools/subversion/subversion_1.13.0.bb index 37b8ca3602..34c0dbe5b8 100644 --- a/meta/recipes-devtools/subversion/subversion_1.13.0.bb +++ b/meta/recipes-devtools/subversion/subversion_1.13.0.bb @@ -12,6 +12,7 @@ SRC_URI = "${APACHE_MIRROR}/${BPN}/${BPN}-${PV}.tar.bz2 \ file://disable_macos.patch \ file://0001-Fix-libtool-name-in-configure.ac.patch \ file://serfmacro.patch \ + file://CVE-2020-17525.patch \ " SRC_URI[md5sum] = "3004b4dae18bf45a0b6ea4ef8820064d" -- cgit v1.2.3-54-g00ecf