Skip to content

Libclamav: harden XLM drawing group length checks #1707

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Open
val-ms wants to merge 1 commit into
base: main
Choose a base branch
from
+11 −0
Open

Libclamav: harden XLM drawing group length checks #1707

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
11 changes: 11 additions & 0 deletions libclamav/xlm_extract.c
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -29,6 +29,7 @@

#include <fcntl.h>
#include <stdbool.h>
#include <stdint.h>

#include "fmap.h"
#include "entconv.h"
Expand Down Expand Up @@ -4791,6 +4792,11 @@ cl_error_t cli_extract_xlm_macros_and_images(const char *dir, cli_ctx *ctx, char

} else {
/* already found the beginning of a drawing group, extract the remaining chunks */
if (drawinggroup_len > SIZE_MAX - biff_header.length) {
cli_dbgmsg("[cli_extract_xlm_macros_and_images] Drawing group length overflow\n");
status = CL_EFORMAT;
goto done;
}
drawinggroup_len += biff_header.length;
CLI_MAX_REALLOC_OR_GOTO_DONE(drawinggroup, drawinggroup_len, status = CL_EMEM);
memcpy(drawinggroup + (drawinggroup_len - biff_header.length), data, biff_header.length);
Expand All @@ -4802,6 +4808,11 @@ cl_error_t cli_extract_xlm_macros_and_images(const char *dir, cli_ctx *ctx, char
if ((OPC_MSODRAWINGGROUP == previous_biff8_opcode) &&
(NULL != drawinggroup)) {
/* already found the beginning of an image, extract the remaining chunks */
if (drawinggroup_len > SIZE_MAX - biff_header.length) {
cli_dbgmsg("[cli_extract_xlm_macros_and_images] Drawing group length overflow\n");
status = CL_EFORMAT;
goto done;
}
drawinggroup_len += biff_header.length;
CLI_MAX_REALLOC_OR_GOTO_DONE(drawinggroup, drawinggroup_len, status = CL_EMEM);
memcpy(drawinggroup + (drawinggroup_len - biff_header.length), data, biff_header.length);
Expand Down
Loading