0a442d05cf
Signed-off-by: Gustavo Zacarias <gustavo@zacarias.com.ar> Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>
66 lines
2.4 KiB
Diff
66 lines
2.4 KiB
Diff
From ee45a34907ffeb5fd95b0513040d8491d565b663 Mon Sep 17 00:00:00 2001
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From: Eldar Zaitov <kyprizel@volema.com>
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Date: Wed, 30 Jan 2013 23:22:27 +0100
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Subject: [PATCH] Curl_sasl_create_digest_md5_message: fix buffer overflow
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When negotiating SASL DIGEST-MD5 authentication, the function
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Curl_sasl_create_digest_md5_message() uses the data provided from the
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server without doing the proper length checks and that data is then
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appended to a local fixed-size buffer on the stack.
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This vulnerability can be exploited by someone who is in control of a
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server that a libcurl based program is accessing with POP3, SMTP or
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IMAP. For applications that accept user provided URLs, it is also
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thinkable that a malicious user would feed an application with a URL to
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a server hosting code targetting this flaw.
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Bug: http://curl.haxx.se/docs/adv_20130206.html
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---
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lib/curl_sasl.c | 23 ++++++-----------------
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1 file changed, 6 insertions(+), 17 deletions(-)
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diff --git a/lib/curl_sasl.c b/lib/curl_sasl.c
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index 57116b6..d07387d 100644
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--- a/lib/curl_sasl.c
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+++ b/lib/curl_sasl.c
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@@ -346,9 +346,7 @@ CURLcode Curl_sasl_create_digest_md5_message(struct SessionHandle *data,
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snprintf(&HA1_hex[2 * i], 3, "%02x", digest[i]);
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/* Prepare the URL string */
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- strcpy(uri, service);
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- strcat(uri, "/");
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- strcat(uri, realm);
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+ snprintf(uri, sizeof(uri), "%s/%s", service, realm);
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/* Calculate H(A2) */
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ctxt = Curl_MD5_init(Curl_DIGEST_MD5);
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@@ -392,20 +390,11 @@ CURLcode Curl_sasl_create_digest_md5_message(struct SessionHandle *data,
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for(i = 0; i < MD5_DIGEST_LEN; i++)
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snprintf(&resp_hash_hex[2 * i], 3, "%02x", digest[i]);
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- strcpy(response, "username=\"");
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- strcat(response, userp);
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- strcat(response, "\",realm=\"");
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- strcat(response, realm);
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- strcat(response, "\",nonce=\"");
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- strcat(response, nonce);
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- strcat(response, "\",cnonce=\"");
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- strcat(response, cnonce);
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- strcat(response, "\",nc=");
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- strcat(response, nonceCount);
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- strcat(response, ",digest-uri=\"");
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- strcat(response, uri);
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- strcat(response, "\",response=");
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- strcat(response, resp_hash_hex);
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+ snprintf(response, sizeof(response),
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+ "username=\"%s\",realm=\"%s\",nonce=\"%s\","
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+ "cnonce=\"%s\",nc=\"%s\",digest-uri=\"%s\",response=%s",
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+ userp, realm, nonce,
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+ cnonce, nonceCount, uri, resp_hash_hex);
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/* Base64 encode the reply */
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return Curl_base64_encode(data, response, 0, outptr, outlen);
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--
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1.7.10.4
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