From adc07e8e4ef9ff263c89d6e8f32ab5222e1a45a0 Mon Sep 17 00:00:00 2001
From: OpenWrt community <openwrt-devel@lists.openwrt.org>
Date: Mon, 30 Oct 2023 14:48:38 +0100
Subject: [PATCH] fix: heap-based buffer over-read and application crash

https://nvd.nist.gov/vuln/detail/CVE-2015-7696

CVE: CVE-2015-7696
---
 crypt.c | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/crypt.c b/crypt.c
index 784e411..a8975f2 100644
--- a/crypt.c
+++ b/crypt.c
@@ -465,7 +465,17 @@ int decrypt(__G__ passwrd)
     GLOBAL(pInfo->encrypted) = FALSE;
     defer_leftover_input(__G);
     for (n = 0; n < RAND_HEAD_LEN; n++) {
-        b = NEXTBYTE;
+        /* 2012-11-23 SMS.  (OUSPG report.)
+         * Quit early if compressed size < HEAD_LEN.  The resulting
+         * error message ("unable to get password") could be improved,
+         * but it's better than trying to read nonexistent data, and
+         * then continuing with a negative G.csize.  (See
+         * fileio.c:readbyte()).
+         */
+        if ((b = NEXTBYTE) == (ush)EOF)
+        {
+            return PK_ERR;
+        }
         h[n] = (uch)b;
         Trace((stdout, " (%02x)", h[n]));
     }
--