File openssl-CVE-2017-3731.patch of Package openssl.20898

Overview Repositories Revisions Requests Users Attributes Meta

File openssl-CVE-2017-3731.patch of Package openssl.20898

commit 51d009043670a627d6abe66894126851cf3690e9
Author: Andy Polyakov <appro@openssl.org>
Date:   Thu Jan 19 00:17:30 2017 +0100

crypto/evp: harden RC4_MD5 cipher.
    
    Originally a crash in 32-bit build was reported CHACHA20-POLY1305
    cipher. The crash is triggered by truncated packet and is result
    of excessive hashing to the edge of accessible memory (or bogus
    MAC value is produced if x86 MD5 assembly module is involved). Since
    hash operation is read-only it is not considered to be exploitable
    beyond a DoS condition.
    
    Thanks to Robert Święcki for report.
    
    CVE-2017-3731
    
    Reviewed-by: Rich Salz <rsalz@openssl.org>

diff --git a/crypto/evp/e_rc4_hmac_md5.c b/crypto/evp/e_rc4_hmac_md5.c
index 5e92855..93cfe3f 100644
--- a/crypto/evp/e_rc4_hmac_md5.c
+++ b/crypto/evp/e_rc4_hmac_md5.c
@@ -269,6 +269,8 @@ static int rc4_hmac_md5_ctrl(EVP_CIPHER_CTX *ctx, int type, int arg,
             len = p[arg - 2] << 8 | p[arg - 1];
 
             if (!ctx->encrypt) {
+                if (len < MD5_DIGEST_LENGTH)
+                    return -1;
                 len -= MD5_DIGEST_LENGTH;
                 p[arg - 2] = len >> 8;
                 p[arg - 1] = len;

Places

File openssl-CVE-2017-3731.patch of Package openssl.20898

Places