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-rw-r--r--lib/stdlib/src/zip.erl82
-rw-r--r--lib/stdlib/test/zip_SUITE.erl50
-rw-r--r--lib/stdlib/test/zip_SUITE_data/exploit.zipbin0 -> 797 bytes
3 files changed, 109 insertions, 23 deletions
diff --git a/lib/stdlib/src/zip.erl b/lib/stdlib/src/zip.erl
index f8ba6f18e9..340cc21390 100644
--- a/lib/stdlib/src/zip.erl
+++ b/lib/stdlib/src/zip.erl
@@ -279,7 +279,8 @@ do_openzip_get(F, #openzip{files = Files, in = In0, input = Input,
case file_name_search(F, Files) of
{#zip_file{offset = Offset},_}=ZFile ->
In1 = Input({seek, bof, Offset}, In0),
- case get_z_file(In1, Z, Input, Output, [], fun silent/1, CWD, ZFile) of
+ case get_z_file(In1, Z, Input, Output, [], fun silent/1,
+ CWD, ZFile, fun all/1) of
{file, R, _In2} -> {ok, R};
_ -> throw(file_not_found)
end;
@@ -1403,9 +1404,10 @@ get_z_files([{#zip_file{offset = Offset},_} = ZFile | Rest], Z, In0,
true ->
In1 = Input({seek, bof, Offset}, In0),
{In2, Acc1} =
- case get_z_file(In1, Z, Input, Output, OpO, FB, CWD, ZFile) of
+ case get_z_file(In1, Z, Input, Output, OpO, FB,
+ CWD, ZFile, Filter) of
{file, GZD, Inx} -> {Inx, [GZD | Acc0]};
- {dir, Inx} -> {Inx, Acc0}
+ {_, Inx} -> {Inx, Acc0}
end,
get_z_files(Rest, Z, In2, Opts, Acc1);
_ ->
@@ -1413,7 +1415,8 @@ get_z_files([{#zip_file{offset = Offset},_} = ZFile | Rest], Z, In0,
end.
%% get a file from the archive, reading chunks
-get_z_file(In0, Z, Input, Output, OpO, FB, CWD, {ZipFile,Extra}) ->
+get_z_file(In0, Z, Input, Output, OpO, FB,
+ CWD, {ZipFile,Extra}, Filter) ->
case Input({read, ?LOCAL_FILE_HEADER_SZ}, In0) of
{eof, In1} ->
{eof, In1};
@@ -1433,29 +1436,64 @@ get_z_file(In0, Z, Input, Output, OpO, FB, CWD, {ZipFile,Extra}) ->
end,
{BFileN, In3} = Input({read, FileNameLen + ExtraLen}, In1),
{FileName, _} = get_file_name_extra(FileNameLen, ExtraLen, BFileN),
- FileName1 = add_cwd(CWD, FileName),
- case lists:last(FileName) of
- $/ ->
- %% perhaps this should always be done?
- Output({ensure_dir,FileName1},[]),
- {dir, In3};
- _ ->
- %% FileInfo = local_file_header_to_file_info(LH)
- %%{Out, In4, CRC, UncompSize} =
- {Out, In4, CRC, _UncompSize} =
- get_z_data(CompMethod, In3, FileName1,
- CompSize, Input, Output, OpO, Z),
- In5 = skip_z_data_descriptor(GPFlag, Input, In4),
- %% TODO This should be fixed some day:
- %% In5 = Input({set_file_info, FileName, FileInfo#file_info{size=UncompSize}}, In4),
- FB(FileName),
- CRC =:= CRC32 orelse throw({bad_crc, FileName}),
- {file, Out, In5}
+ ReadAndWrite =
+ case check_valid_location(CWD, FileName) of
+ {true,FileName1} ->
+ true;
+ {false,FileName1} ->
+ Filter({ZipFile#zip_file{name = FileName1},Extra})
+ end,
+ case ReadAndWrite of
+ true ->
+ case lists:last(FileName) of
+ $/ ->
+ %% perhaps this should always be done?
+ Output({ensure_dir,FileName1},[]),
+ {dir, In3};
+ _ ->
+ %% FileInfo = local_file_header_to_file_info(LH)
+ %%{Out, In4, CRC, UncompSize} =
+ {Out, In4, CRC, _UncompSize} =
+ get_z_data(CompMethod, In3, FileName1,
+ CompSize, Input, Output, OpO, Z),
+ In5 = skip_z_data_descriptor(GPFlag, Input, In4),
+ %% TODO This should be fixed some day:
+ %% In5 = Input({set_file_info, FileName,
+ %% FileInfo#file_info{size=UncompSize}}, In4),
+ FB(FileName),
+ CRC =:= CRC32 orelse throw({bad_crc, FileName}),
+ {file, Out, In5}
+ end;
+ false ->
+ {ignore, In3}
end;
_ ->
throw(bad_local_file_header)
end.
+%% make sure FileName doesn't have relative path that points over CWD
+check_valid_location(CWD, FileName) ->
+ %% check for directory traversal exploit
+ case check_dir_level(filename:split(FileName), 0) of
+ {FileOrDir,Level} when Level < 0 ->
+ CWD1 = if CWD == "" -> "./";
+ true -> CWD
+ end,
+ error_logger:format("Illegal path: ~ts, extracting in ~ts~n",
+ [add_cwd(CWD,FileName),CWD1]),
+ {false,add_cwd(CWD, FileOrDir)};
+ _ ->
+ {true,add_cwd(CWD, FileName)}
+ end.
+
+check_dir_level([FileOrDir], Level) ->
+ {FileOrDir,Level};
+check_dir_level(["." | Parts], Level) ->
+ check_dir_level(Parts, Level);
+check_dir_level([".." | Parts], Level) ->
+ check_dir_level(Parts, Level-1);
+check_dir_level([_Dir | Parts], Level) ->
+ check_dir_level(Parts, Level+1).
get_file_name_extra(FileNameLen, ExtraLen, B) ->
case B of
diff --git a/lib/stdlib/test/zip_SUITE.erl b/lib/stdlib/test/zip_SUITE.erl
index 2add5a39a2..7d90795c9e 100644
--- a/lib/stdlib/test/zip_SUITE.erl
+++ b/lib/stdlib/test/zip_SUITE.erl
@@ -25,6 +25,7 @@
zip_to_binary/1,
unzip_options/1, zip_options/1, list_dir_options/1, aliases/1,
openzip_api/1, zip_api/1, open_leak/1, unzip_jar/1,
+ unzip_traversal_exploit/1,
compress_control/1,
foldl/1]).
@@ -38,7 +39,8 @@ all() ->
[borderline, atomic, bad_zip, unzip_from_binary,
unzip_to_binary, zip_to_binary, unzip_options,
zip_options, list_dir_options, aliases, openzip_api,
- zip_api, open_leak, unzip_jar, compress_control, foldl].
+ zip_api, open_leak, unzip_jar, compress_control, foldl,
+ unzip_traversal_exploit].
groups() ->
[].
@@ -377,6 +379,52 @@ unzip_options(Config) when is_list(Config) ->
0 = delete_files([Subdir]),
ok.
+%% Test that unzip handles directory traversal exploit (OTP-13633)
+unzip_traversal_exploit(Config) ->
+ DataDir = proplists:get_value(data_dir, Config),
+ PrivDir = proplists:get_value(priv_dir, Config),
+ ZipName = filename:join(DataDir, "exploit.zip"),
+
+ %% $ zipinfo -1 test/zip_SUITE_data/exploit.zip
+ %% clash.txt
+ %% ../clash.txt
+ %% ../above.txt
+ %% subdir/../in_root_dir.txt
+
+ %% create a temp directory
+ SubDir = filename:join(PrivDir, "exploit_test"),
+ ok = file:make_dir(SubDir),
+
+ ClashFile = filename:join(SubDir,"clash.txt"),
+ AboveFile = filename:join(SubDir,"above.txt"),
+ RelativePathFile = filename:join(SubDir,"subdir/../in_root_dir.txt"),
+
+ %% unzip in SubDir
+ {ok, [ClashFile, ClashFile, AboveFile, RelativePathFile]} =
+ zip:unzip(ZipName, [{cwd,SubDir}]),
+
+ {ok,<<"This file will overwrite other file.\n">>} =
+ file:read_file(ClashFile),
+ {ok,_} = file:read_file(AboveFile),
+ {ok,_} = file:read_file(RelativePathFile),
+
+ %% clean up
+ delete_files([SubDir]),
+
+ %% create the temp directory again
+ ok = file:make_dir(SubDir),
+
+ %% unzip in SubDir
+ {ok, [ClashFile, AboveFile, RelativePathFile]} =
+ zip:unzip(ZipName, [{cwd,SubDir},keep_old_files]),
+
+ {ok,<<"This is the original file.\n">>} =
+ file:read_file(ClashFile),
+
+ %% clean up
+ delete_files([SubDir]),
+ ok.
+
%% Test unzip a jar file (OTP-7382).
unzip_jar(Config) when is_list(Config) ->
DataDir = proplists:get_value(data_dir, Config),
diff --git a/lib/stdlib/test/zip_SUITE_data/exploit.zip b/lib/stdlib/test/zip_SUITE_data/exploit.zip
new file mode 100644
index 0000000000..afb8dbd192
--- /dev/null
+++ b/lib/stdlib/test/zip_SUITE_data/exploit.zip
Binary files differ
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-04 05:42:30 +0000