ID CVE-2015-3236
Summary cURL and libcurl 7.40.0 through 7.42.1 send the HTTP Basic authentication credentials for a previous connection when reusing a reset (curl_easy_reset) connection handle to send a request to the same host name, which allows remote attackers to obtain sensitive information via unspecified vectors.
Vulnerable Configurations
  • Haxx Curl 7.40.0
  • Haxx Curl 7.41.0
  • Haxx Curl 7.42.0
  • Haxx Curl 7.42.1
  • Haxx libcurl 7.40.0
  • Haxx libcurl 7.41.0
  • Haxx libcurl 7.42.0
  • Haxx libcurl 7.42.1
Base: 5.0 (as of 16-08-2016 - 09:36)
  • Subverting Environment Variable Values
    The attacker directly or indirectly modifies environment variables used by or controlling the target software. The attacker's goal is to cause the target software to deviate from its expected operation in a manner that benefits the attacker.
  • Footprinting
    An attacker engages in probing and exploration activity to identify constituents and properties of the target. Footprinting is a general term to describe a variety of information gathering techniques, often used by attackers in preparation for some attack. It consists of using tools to learn as much as possible about the composition, configuration, and security mechanisms of the targeted application, system or network. Information that might be collected during a footprinting effort could include open ports, applications and their versions, network topology, and similar information. While footprinting is not intended to be damaging (although certain activities, such as network scans, can sometimes cause disruptions to vulnerable applications inadvertently) it may often pave the way for more damaging attacks.
  • Exploiting Trust in Client (aka Make the Client Invisible)
    An attack of this type exploits a programs' vulnerabilities in client/server communication channel authentication and data integrity. It leverages the implicit trust a server places in the client, or more importantly, that which the server believes is the client. An attacker executes this type of attack by placing themselves in the communication channel between client and server such that communication directly to the server is possible where the server believes it is communicating only with a valid client. There are numerous variations of this type of attack.
  • Browser Fingerprinting
    An attacker carefully crafts small snippets of Java Script to efficiently detect the type of browser the potential victim is using. Many web-based attacks need prior knowledge of the web browser including the version of browser to ensure successful exploitation of a vulnerability. Having this knowledge allows an attacker to target the victim with attacks that specifically exploit known or zero day weaknesses in the type and version of the browser used by the victim. Automating this process via Java Script as a part of the same delivery system used to exploit the browser is considered more efficient as the attacker can supply a browser fingerprinting method and integrate it with exploit code, all contained in Java Script and in response to the same web page request by the browser.
  • Session Credential Falsification through Prediction
    This attack targets predictable session ID in order to gain privileges. The attacker can predict the session ID used during a transaction to perform spoofing and session hijacking.
  • Reusing Session IDs (aka Session Replay)
    This attack targets the reuse of valid session ID to spoof the target system in order to gain privileges. The attacker tries to reuse a stolen session ID used previously during a transaction to perform spoofing and session hijacking. Another name for this type of attack is Session Replay.
  • Using Slashes in Alternate Encoding
    This attack targets the encoding of the Slash characters. An attacker would try to exploit common filtering problems related to the use of the slashes characters to gain access to resources on the target host. Directory-driven systems, such as file systems and databases, typically use the slash character to indicate traversal between directories or other container components. For murky historical reasons, PCs (and, as a result, Microsoft OSs) choose to use a backslash, whereas the UNIX world typically makes use of the forward slash. The schizophrenic result is that many MS-based systems are required to understand both forms of the slash. This gives the attacker many opportunities to discover and abuse a number of common filtering problems. The goal of this pattern is to discover server software that only applies filters to one version, but not the other.
nessus via4
  • NASL family Fedora Local Security Checks
    NASL id FEDORA_2015-10155.NASL
    description - implement public key pinning for NSS backend (#1195771) - fix lingering HTTP credentials in connection re-use (CVE-2015-3236) - prevent SMB from sending off unrelated memory contents (CVE-2015-3237) - curl-config --libs now works on x86_64 without libcurl-devel.x86_64 (#1228363) Note that Tenable Network Security has extracted the preceding description block directly from the Fedora security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.
    last seen 2019-02-21
    modified 2016-05-16
    plugin id 84376
    published 2015-06-25
    reporter Tenable
    title Fedora 22 : curl-7.40.0-5.fc22 (2015-10155)
  • NASL family FreeBSD Local Security Checks
    NASL id FREEBSD_PKG_2438D4AF153811E5A1063C970E169BC2.NASL
    description cURL reports : libcurl can wrongly send HTTP credentials when re-using connections. libcurl allows applications to set credentials for the upcoming transfer with HTTP Basic authentication, like with CURLOPT_USERPWD for example. Name and password. Just like all other libcurl options the credentials are sticky and are kept associated with the 'handle' until something is made to change the situation. Further, libcurl offers a curl_easy_reset() function that resets a handle back to its pristine state in terms of all settable options. A reset is of course also supposed to clear the credentials. A reset is typically used to clear up the handle and prepare it for a new, possibly unrelated, transfer. Within such a handle, libcurl can also store a set of previous connections in case a second transfer is requested to a host name for which an existing connection is already kept alive. With this flaw present, using the handle even after a reset would make libcurl accidentally use those credentials in a subsequent request if done to the same host name and connection as was previously accessed. An example case would be first requesting a password protected resource from one section of a website, and then do a second request of a public resource from a completely different part of the site without authentication. This flaw would then inadvertently leak the credentials in the second request. libcurl can get tricked by a malicious SMB server to send off data it did not intend to. In libcurl's state machine function handling the SMB protocol (smb_request_state()), two length and offset values are extracted from data that has arrived over the network, and those values are subsequently used to figure out what data range to send back. The values are used and trusted without boundary checks and are just assumed to be valid. This allows carefully handcrafted packages to trick libcurl into responding and sending off data that was not intended. Or just crash if the values cause libcurl to access invalid memory.
    last seen 2019-02-21
    modified 2018-12-19
    plugin id 84254
    published 2015-06-18
    reporter Tenable
    title FreeBSD : cURL -- Multiple Vulnerability (2438d4af-1538-11e5-a106-3c970e169bc2)
  • NASL family SuSE Local Security Checks
    NASL id OPENSUSE-2015-446.NASL
    description Curl was updated to fix two security issues and enable metalink support The following vulnerabilities were fixed : - CVE-2015-3236: libcurl could have wrongly send HTTP credentials when re-using connections (boo#934501) - CVE-2015-3237: libcurl could have been tricked by a malicious SMB server to send off data it did not intend to (boo#934502) The following feature was enabled : - boo#851126: enable metalink support.
    last seen 2019-02-21
    modified 2016-05-16
    plugin id 84387
    published 2015-06-25
    reporter Tenable
    title openSUSE Security Update : curl (openSUSE-2015-446)
  • NASL family Amazon Linux Local Security Checks
    NASL id ALA_ALAS-2015-551.NASL
    description As discussed upstream, libcurl can wrongly send HTTP credentials when re-using connections. (CVE-2015-3236) Also discussed upstream, libcurl can get tricked by a malicious SMB server to send off data it did not intend to. (CVE-2015-3237)
    last seen 2019-02-21
    modified 2018-12-18
    plugin id 84293
    published 2015-06-22
    reporter Tenable
    title Amazon Linux AMI : curl (ALAS-2015-551)
  • NASL family Gentoo Local Security Checks
    NASL id GENTOO_GLSA-201509-02.NASL
    description The remote host is affected by the vulnerability described in GLSA-201509-02 (cURL: Multiple vulnerabilities) Multiple vulnerabilities have been discovered in cURL. Please review the CVE identifiers referenced below for details. Impact : A remote attacker could possibly obtain sensitive information, or cause a Denial of Service condition. Workaround : There is no known workaround at this time.
    last seen 2019-02-21
    modified 2016-05-16
    plugin id 86133
    published 2015-09-25
    reporter Tenable
    title GLSA-201509-02 : cURL: Multiple vulnerabilities
  • NASL family Slackware Local Security Checks
    NASL id SLACKWARE_SSA_2015-302-01.NASL
    description New curl packages are available for Slackware 13.0, 13.1, 13.37, 14.0, 14.1, and -current to fix security issues.
    last seen 2019-02-21
    modified 2016-05-16
    plugin id 86662
    published 2015-10-30
    reporter Tenable
    title Slackware 13.0 / 13.1 / 13.37 / 14.0 / 14.1 / current : curl (SSA:2015-302-01)
refmap via4
  • 75385
  • 91787
fedora FEDORA-2015-10155
gentoo GLSA-201509-02
Last major update 21-12-2016 - 21:59
Published 22-06-2015 - 15:59
Last modified 16-10-2018 - 21:29
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