CVE-2018-1000120

A buffer overflow exists in curl 7.12.3 to and including curl 7.58.0 in the FTP URL handling that allows an attacker to cause a denial of service or worse.

A buffer overflow exists in curl 7.12.3 to and including curl 7.58.0 in the FTP URL handling that allows an attacker to cause a denial of service or worse.

curl can be coerced into writing a zero byte out of bounds.

This bug can trigger when curl is told to work on an FTP URL, with the setting to only issue a single CWD command (--ftp-method singlecwd or the libcurl alternative CURLOPT_FTP_FILEMETHOD).

curl then URL-decodes the given path, calls strlen() on the result and deducts the length of the file name part to find the end of the directory within the buffer. It then writes a zero byte on that index, in a buffer allocated on the heap.

If the directory part of the URL contains a %00 sequence, the directory length might end up shorter than the file name path, making the calculation size_t index = directory_len - filepart_len end up with a huge index variable for where the zero byte gets stored: heap_buffer[index] = 0. On several architectures that huge index will wrap and work as a negative value, thus overwriting memory before the intended heap buffer.

By using different file part lengths and putting the string %00 in different places in the URL, an attacker that can control what paths a curl-using application uses can write that zero byte on different indexes.

A buffer overflow exists in curl 7.12.3 to and including curl 7.58.0 in the FTP URL handling that allows an attacker to cause a denial of service or worse.

• CVE-2018-1000120: fix buffer overflow exists in the FTP URL handling
• CVE-2018-1000007: fix leak authentication data to third parties in HTTP requests

• CVE-2018-1000120: fix buffer overflow exists in the FTP URL handling
• CVE-2018-1000007: fix leak authentication data to third parties in HTTP requests

curl can be fooled into writing a zero byte out of bounds.

This bug can trigger when curl is told to work on an FTP URL, with the setting to only issue a single CWD command (--ftp-method singlecwd or the libcurl alternative CURLOPT_FTP_FILEMETHOD).

curl then URL-decodes the given path, calls strlen() on the result and deducts the length of the filename part to find the end of the directory within the buffer. It then writes a zero byte on that index, in a buffer allocated on the heap.

If the directory part of the URL contains a "%00" sequence, the directory length might end up shorter than the filename path, making the calculation size_t index = directory_len - filepart_len end up with a huge index variable for where the zero byte gets stored: heap_buffer[index] = 0. On several architectures that huge index wraps and works as a negative value, thus overwriting memory before the intended heap buffer.

By using different file part lengths and putting %00 in different places in the URL, an attacker that can control what paths a curl-using application uses can write that zero byte on different indexes.

Updated curl packages fix security vulnerabilities:

Peter Wu discovered that curl incorrectly handled certain SMTP buffers. A remote attacker could use this issue to cause curl to crash, resulting in a denial of service, or possibly execute arbitrary code (CVE-2018-0500).

Zhaoyang Wu discovered that cURL, an URL transfer library, contains a buffer overflow in the NTLM authentication code triggered by passwords that exceed 2GB in length on 32bit systems (CVE-2018-14618).

Phan Thanh discovered that curl incorrectly handled certain FTP paths. An attacker could use this to cause a denial of service or possibly execute arbitrary code (CVE-2018-1000120).

Dario Weisser discovered that curl incorrectly handled certain LDAP URLs. An attacker could possibly use this issue to cause a denial of service (CVE-2018-1000121).

Max Dymond discovered that curl incorrectly handled certain RTSP data. An attacker could possibly use this to cause a denial of service or even to get access to sensitive data (CVE-2018-1000122).

A heap-based buffer overflow can happen when closing down an FTP connection with very long server command replies. When doing FTP transfers, curl keeps a spare "closure handle" around internally that will be used when an FTP connection gets shut down since the original curl easy handle is then already removed. FTP server response data that gets cached from the original transfer might then be larger than the default buffer size (16 KB) allocated in the "closure handle", which can lead to a buffer overwrite. The contents and size of that overwrite is controllable by the server (CVE-2018-1000300).

curl can be tricked into reading data beyond the end of a heap based buffer used to store downloaded content. When servers send RTSP responses back to curl, the data starts out with a set of headers. curl parses that data to separate it into a number of headers to deal with those appropriately and to find the end of the headers that signal the start of the "body" part. The function that splits up the response into headers is called "Curl_http_readwrite_headers()" and in situations where it can't find a single header in the buffer, it might end up leaving a pointer pointing into the buffer instead of to the start of the buffer which then later on may lead to an out of buffer read when code assumes that pointer points to a full buffer size worth of memory to use. This could potentially lead to information leakage but most likely a crash/denial of service for applications if a server triggers this flaw (CVE-2018-1000301).

These are all security issues fixed in the curl-7.79.1-1.1 package on the GA media of openSUSE Tumbleweed.

This update for curl fixes the following issues:

Following security issues were fixed:

• CVE-2018-1000120: A buffer overflow exists in the FTP URL handling that allowed an attacker to cause a denial of service or possible code execution (bsc#1084521).
• CVE-2018-1000121: A NULL pointer dereference exists in the LDAP code that allowed an attacker to cause a denial of service (bsc#1084524).
• CVE-2018-1000122: A buffer over-read exists in the RTSP+RTP handling code that allowed an attacker to cause a denial of service or information leakage (bsc#1084532).

This update for curl fixes the following issues:

curl was updated to version 7.37.0 (fate#325339 bsc#1084137)

This update syncs the curl version to the one in SUSE Linux Enterprise 12 and is full binary compatible to the previous version.

This update is done to allow other third party software like 'R' to be able to be used on the SUSE Linux Enterprise 11 codebase.

Following security issues were fixed:

• CVE-2018-1000120: A buffer overflow exists in the FTP URL handling that allowed an attacker to cause a denial of service or possible code execution (bsc#1084521).
• CVE-2018-1000121: A NULL pointer dereference exists in the LDAP code that allowed an attacker to cause a denial of service (bsc#1084524).
• CVE-2018-1000122: A buffer over-read exists in the RTSP+RTP handling code that allowed an attacker to cause a denial of service or information leakage (bsc#1084532).

The package also requires a libopenssl that implements the DEFAULT_SUSE cipher list (bsc#1081056, bsc#1083463,bsc#1086825)

This update for curl fixes the following security issues:

• CVE-2018-1000120: Prevent buffer overflow in the FTP URL handling that allowed an attacker to cause a denial of service (bsc#1084521).
• CVE-2018-14618: Prevent integer overflow in the NTLM authentication code (bsc#1106019)

Phan Thanh discovered that curl incorrectly handled certain FTP paths. An attacker could use this to cause a denial of service or possibly execute arbitrary code. (CVE-2018-1000120)

Dario Weisser discovered that curl incorrectly handled certain LDAP URLs. An attacker could possibly use this issue to cause a denial of service. (CVE-2018-1000121)

Max Dymond discovered that curl incorrectly handled certain RTSP data. An attacker could possibly use this to cause a denial of service or even to get access to sensitive data. (CVE-2018-1000122)