From 15b160780c6eeff7048063c099a7f8757e1d8391 Mon Sep 17 00:00:00 2001 From: "A. Wilcox" Date: Mon, 17 Jun 2019 22:02:34 +0000 Subject: system/abuild: close keyhole vulnerability --- system/abuild/keyhole.patch | 72 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 72 insertions(+) create mode 100644 system/abuild/keyhole.patch (limited to 'system/abuild/keyhole.patch') diff --git a/system/abuild/keyhole.patch b/system/abuild/keyhole.patch new file mode 100644 index 000000000..206bd6c2e --- /dev/null +++ b/system/abuild/keyhole.patch @@ -0,0 +1,72 @@ +From 4f90ce92778d0ee302e288def75591b96a397c8b Mon Sep 17 00:00:00 2001 +From: Max Rees +Date: Thu, 13 Jun 2019 23:19:54 -0400 +Subject: [PATCH] abuild-sudo: don't allow --keys-dir + +Not allowing --allow-untrusted is obviously a good idea, but it can be +trivially bypassed if --keys-dir is allowed: + +$ abuild-apk add foo-1-r0.apk +ERROR: foo-1-r0.apk: UNTRUSTED signature +$ abuild-apk --allow-untrusted add foo-1-r0.apk +abuild-apk: --allow-untrusted: not allowed option +$ cp -rp /etc/apk/keys /tmp/keys +$ cp untrusted.pub /tmp/keys +$ abuild-apk --keys-dir /tmp/keys add foo-1-r0.apk +(1/1) Installing foo (1-r0) +OK: 4319 MiB in 806 packages + +If both --allow-untrusted and --keys-dir are not allowed, then it should +no longer be possible for an unprivileged member of the abuild group to +add an untrusted package. + +$ abuild-apk --keys-dir /tmp/keys add foo-1-r0.apk +abuild-apk: --keys-dir: not allowed option +--- + abuild-sudo.c | 18 +++++++++++++++--- + 1 file changed, 15 insertions(+), 3 deletions(-) + +diff --git a/abuild-sudo.c b/abuild-sudo.c +index 80ceb8d7dd..12d64f13fd 100644 +--- a/abuild-sudo.c ++++ b/abuild-sudo.c +@@ -32,6 +32,12 @@ static const char* valid_cmds[] = { + NULL + }; + ++static const char* invalid_opts[] = { ++ "--allow-untrusted", ++ "--keys-dir", ++ NULL, ++}; ++ + const char *get_command_path(const char *cmd) + { + const char *p; +@@ -46,6 +52,14 @@ const char *get_command_path(const char *cmd) + return NULL; + } + ++void check_option(const char *opt) ++{ ++ int i; ++ for (i = 0; invalid_opts[i] != NULL; i++) ++ if (strcmp(opt, invalid_opts[i]) == 0) ++ errx(1, "%s: not allowed option", opt); ++} ++ + int is_in_group(gid_t group) + { + int ngroups_max = sysconf(_SC_NGROUPS_MAX) + 1; +@@ -105,10 +119,8 @@ int main(int argc, const char *argv[]) + if (path == NULL) + errx(1, "%s: Not a valid subcommand", cmd); + +- /* we dont allow --allow-untrusted option */ + for (i = 1; i < argc; i++) +- if (strcmp(argv[i], "--allow-untrusted") == 0) +- errx(1, "%s: not allowed option", "--allow-untrusted"); ++ check_option(argv[i]); + + argv[0] = path; + /* set our uid to root so bbsuid --install works */ -- cgit v1.2.3-60-g2f50