New Denial Of Service Attack Cripples Servers Slowly
'Slow Read' proof-of-concept and tool released Thursday.
A researcher Thursday published proof-of-concept code that takes a different spin on the slow HTTP denial-of-service (DoS) attack simply by dragging out the process of reading the server's response--and ultimately overwhelming it.
Sergey Shekyan, senior software engineer with Qualys, also has added this new so-called Slow Read attack to his open-source slowhttptest tool.
Slow Read basically sends a legitimate HTTP request and then very slowly reads the response, thus keeping as many open connections as possible and eventually causing a DoS.
Shekyan's Slowhttptest attack tool initially was inspired by related open-source tools Slowloris and OWASP's Slow HTTP Post. Slowloris keeps connections open by sending partial HTTP requests and sends headers at regular intervals to prevent the sockets from closing, while the Slow HTTP POST distributed DoS (DDoS) tool simulates an attack using POST headers with a legitimate "content-length" field that lets the Web server know how much data is arriving. Once the headers are sent, the POST message body is transmitted slowly, thus gridlocking the connection and server resources.
Slow HTTP attacks are gaining in popularity among the bad guys as a way to quietly wage a DoS attack because these exploits are relatively easy to perform, require minimal computing resources, and often are tough to detect until it's too late.
Published: 2014-11-26 Openswan 2.6.40 allows remote attackers to cause a denial of service (NULL pointer dereference and IKE daemon restart) via IKEv2 packets that lack expected payloads. NOTE: this vulnerability exists because of an incomplete fix for CVE 2013-6466.
Published: 2014-11-26 The res_pjsip_pubsub module in Asterisk Open Source 12.x before 12.5.1 allows remote authenticated users to cause a denial of service (crash) via crafted headers in a SIP SUBSCRIBE request for an event package.
Published: 2014-11-26 Asterisk Open Source 11.x before 11.12.1 and 12.x before 12.5.1 and Certified Asterisk 11.6 before 11.6-cert6, when using the res_fax_spandsp module, allows remote authenticated users to cause a denial of service (crash) via an out of call message, which is not properly handled in the ReceiveFax dia...
Published: 2014-11-26 The pinger in Squid 3.x before 3.4.8 allows remote attackers to obtain sensitive information or cause a denial of service (out-of-bounds read and crash) via a crafted type in an (1) ICMP or (2) ICMP6 packet.