From d36661703e16bd740a3a928041b1e697a6617b98 Mon Sep 17 00:00:00 2001
From: Daniel Stenberg <daniel@haxx.se>
Date: Thu, 9 Jun 2022 09:27:24 +0200
Subject: [PATCH] krb5: return error properly on decode errors
Bug: https://curl.se/docs/CVE-2022-32208.html
CVE-2022-32208
Reported-by: Harry Sintonen
Closes #9051
Upstream-commit: 6ecdf5136b52af747e7bda08db9a748256b1cd09
Signed-off-by: Kamil Dudka <kdudka@redhat.com>
---
lib/krb5.c | 5 +----
lib/security.c | 19 +++++++++++++++----
2 files changed, 16 insertions(+), 8 deletions(-)
diff --git a/lib/krb5.c b/lib/krb5.c
index 787137c..6f9e1f7 100644
--- a/lib/krb5.c
+++ b/lib/krb5.c
@@ -86,11 +86,8 @@ krb5_decode(void *app_data, void *buf, int len,
enc.value = buf;
enc.length = len;
maj = gss_unwrap(&min, *context, &enc, &dec, NULL, NULL);
- if(maj != GSS_S_COMPLETE) {
- if(len >= 4)
- strcpy(buf, "599 ");
+ if(maj != GSS_S_COMPLETE)
return -1;
- }
memcpy(buf, dec.value, dec.length);
len = curlx_uztosi(dec.length);
diff --git a/lib/security.c b/lib/security.c
index 52cce97..c95f290 100644
--- a/lib/security.c
+++ b/lib/security.c
@@ -64,6 +64,10 @@
/* The last #include file should be: */
#include "memdebug.h"
+/* Max string input length is a precaution against abuse and to detect junk
+ input easier and better. */
+#define CURL_MAX_INPUT_LENGTH 8000000
+
static const struct {
enum protection_level level;
const char *name;
@@ -192,6 +196,7 @@ static CURLcode read_data(struct connectdata *conn,
{
int len;
CURLcode result;
+ int nread;
result = socket_read(fd, &len, sizeof(len));
if(result)
@@ -200,7 +205,10 @@ static CURLcode read_data(struct connectdata *conn,
if(len) {
/* only realloc if there was a length */
len = ntohl(len);
- buf->data = Curl_saferealloc(buf->data, len);
+ if(len > CURL_MAX_INPUT_LENGTH)
+ len = 0;
+ else
+ buf->data = Curl_saferealloc(buf->data, len);
}
if(!len || !buf->data)
return CURLE_OUT_OF_MEMORY;
@@ -208,8 +216,11 @@ static CURLcode read_data(struct connectdata *conn,
result = socket_read(fd, buf->data, len);
if(result)
return result;
- buf->size = conn->mech->decode(conn->app_data, buf->data, len,
- conn->data_prot, conn);
+ nread = conn->mech->decode(conn->app_data, buf->data, len,
+ conn->data_prot, conn);
+ if(nread < 0)
+ return CURLE_RECV_ERROR;
+ buf->size = (size_t)nread;
buf->index = 0;
return CURLE_OK;
}
--
2.35.3