[exim-cvs] Auths: fix possible OOB read in SPA authenticator…

Gitweb: https://git.exim.org/exim.git/commitdiff/ccf9816f54fb04ab5508eb8c7f00b08bc3531297

Commit:     ccf9816f54fb04ab5508eb8c7f00b08bc3531297
Parent:     936e342d560e218c2aee5cb2295be925c27c2106
Author:     Jeremy Harris <jgh146exb@???>
AuthorDate: Thu May 11 21:08:08 2023 +0100
Committer:  Heiko Schlittermann (HS12-RIPE) <hs@???>
CommitDate: Sat Sep 30 22:49:31 2023 +0200

    Auths: fix possible OOB read in SPA authenticator.  Bug 3001

    (cherry picked from commit 04107e98d58efb69f7e2d7b81176e5374c7098a3)
---
 doc/doc-txt/ChangeLog    |  3 +++
 src/src/auths/auth-spa.c | 36 ++++++++++++++++++++++++++++--------
 2 files changed, 31 insertions(+), 8 deletions(-)

diff --git a/doc/doc-txt/ChangeLog b/doc/doc-txt/ChangeLog
index 97987f014..e1402eae0 100644
--- a/doc/doc-txt/ChangeLog
+++ b/doc/doc-txt/ChangeLog
@@ -199,6 +199,9 @@ JH/40 Bug 2999: Fix a possible OOB write in the external authenticator, which
 JH/41 Bug 3000: Fix a possible OOB write in the SPA authenticator, which could
       be triggered by externally-controlled input.  Found by Trend Micro.

+JH/42 Bug 3001: Fix a possible OOB read in the SPA authenticator, which could
+      be triggered by externally-controlled input.  Found by Trend Micro.
+

Exim version 4.96
-----------------
diff --git a/src/src/auths/auth-spa.c b/src/src/auths/auth-spa.c
index 27e95805b..bb3d327d1 100644
--- a/src/src/auths/auth-spa.c
+++ b/src/src/auths/auth-spa.c
@@ -1254,15 +1254,10 @@ spa_bytes_add(ptr, header, b, len*2); \
}


-#define GetUnicodeString(structPtr, header) \
-unicodeToString(((char*)structPtr) + IVAL(&structPtr->header.offset,0) , SVAL(&structPtr->header.len,0)/2)
-#define GetString(structPtr, header) \
-toString(((CS structPtr) + IVAL(&structPtr->header.offset,0)), SVAL(&structPtr->header.len,0))
-
#ifdef notdef

#define DumpBuffer(fp, structPtr, header) \
-dumpRaw(fp,(US structPtr)+IVAL(&structPtr->header.offset,0),SVAL(&structPtr->header.len,0))
+ dumpRaw(fp,(US structPtr)+IVAL(&structPtr->header.offset,0),SVAL(&structPtr->header.len,0))


static void
@@ -1326,8 +1321,33 @@ buf[len] = 0;
return buf;
}

+static inline uschar *
+get_challenge_unistr(SPAAuthChallenge * challenge, SPAStrHeader * hdr)
+{
+int off = IVAL(&hdr->offset, 0);
+int len = SVAL(&hdr->len, 0);
+return off + len < sizeof(SPAAuthChallenge)
+ ? US unicodeToString(CS challenge + off, len/2) : US"";
+}
+
+static inline uschar *
+get_challenge_str(SPAAuthChallenge * challenge, SPAStrHeader * hdr)
+{
+int off = IVAL(&hdr->offset, 0);
+int len = SVAL(&hdr->len, 0);
+return off + len < sizeof(SPAAuthChallenge)
+ ? US toString(CS challenge + off, len) : US"";
+}
+
#ifdef notdef

+#define GetUnicodeString(structPtr, header) \
+ unicodeToString(((char*)structPtr) + IVAL(&structPtr->header.offset,0) , SVAL(&structPtr->header.len,0)/2)
+
+#define GetString(structPtr, header) \
+ toString(((CS structPtr) + IVAL(&structPtr->header.offset,0)), SVAL(&structPtr->header.len,0))
+
+
void
dumpSmbNtlmAuthRequest (FILE * fp, SPAAuthRequest * request)
{
@@ -1497,8 +1517,8 @@ if (p)
}

else domain = d = string_copy(cf & 0x1
- ? CUS GetUnicodeString(challenge, uDomain)
- : CUS GetString(challenge, uDomain));
+ ? CUS get_challenge_unistr(challenge, &challenge->uDomain)
+ : CUS get_challenge_str(challenge, &challenge->uDomain));

spa_smb_encrypt(password, challenge->challengeData, lmRespData);
spa_smb_nt_encrypt(password, challenge->challengeData, ntRespData);

--
## subscription configuration (requires account):
## https://lists.exim.org/mailman3/postorius/lists/exim-cvs.lists.exim.org/
## unsubscribe (doesn't require an account):
## exim-cvs-unsubscribe@???
## Exim details at http://www.exim.org/
## Please use the Wiki with this list - http://wiki.exim.org/