[XS] Change in openvpn[master]: openvpnserv: don't allow '/' in config paths

Attention is currently required from: d12fk, plaisthos.

Hello plaisthos,

I'd like you to do a code review.
Please visit

    http://gerrit.openvpn.net/c/openvpn/+/1885?usp=email

to review the following change.


Change subject: openvpnserv: don't allow '/' in config paths
......................................................................

openvpnserv: don't allow '/' in config paths

Do not allow forward slashes in user provided config paths. The PathCch*
functions do not treat them as path separators, leading to "/../" not
being canonicalized. That, and the fact that Windows file APIs accept
forward slashes leads to possible directory traversal.

Discovered and reported by BreachX Zero Day Labs, using Typhon AI Mil v2.
Contributing Researcher: Vivek Parikh.

Reported-by: Vivek Parikh <[email protected]>
CVE: 2026-78043
Github: OpenVPN/openvpn-private-issues#162
Change-Id: I371aafba18d336bcfd3912e92c18301e39bf6087
Signed-off-by: Heiko Hund <[email protected]>
---
M src/openvpnserv/validate.c
1 file changed, 5 insertions(+), 0 deletions(-)



  git pull ssh://gerrit.openvpn.net:29418/openvpn refs/changes/85/1885/1

diff --git a/src/openvpnserv/validate.c b/src/openvpnserv/validate.c
index 7c0a87b..e3ef8b6 100644
--- a/src/openvpnserv/validate.c
+++ b/src/openvpnserv/validate.c
@@ -68,6 +68,11 @@
     {
         return FALSE;
     }
+    /* do not accept forward slashes in paths, as PathCch* functions do not handle these */
+    if (wcschr(workdir, L'/') || wcschr(fname, L'/'))
+    {
+        return FALSE;
+    }
     /* convert fname to full canonical path */
     if (PathIsRelativeW(fname))
     {

-- 
To view, visit http://gerrit.openvpn.net/c/openvpn/+/1885?usp=email
To unsubscribe, or for help writing mail filters, visit http://gerrit.openvpn.net/settings?usp=email

Gerrit-MessageType: newchange
Gerrit-Project: openvpn
Gerrit-Branch: master
Gerrit-Change-Id: I371aafba18d336bcfd3912e92c18301e39bf6087
Gerrit-Change-Number: 1885
Gerrit-PatchSet: 1
Gerrit-Owner: cron2 <[email protected]>
Gerrit-Reviewer: d12fk <[email protected]>
Gerrit-Reviewer: plaisthos <[email protected]>
Gerrit-CC: openvpn-devel <[email protected]>
Gerrit-Attention: plaisthos <[email protected]>
Gerrit-Attention: d12fk <[email protected]>

_______________________________________________
Openvpn-devel mailing list
[email protected]
https://lists.sourceforge.net/lists/listinfo/openvpn-devel