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-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA256 =========================================================================== AUSCERT External Security Bulletin Redistribution ESB-2016.1583 CVE-2016-3092: Apache Tomcat Denial of Service 23 June 2016 =========================================================================== AusCERT Security Bulletin Summary --------------------------------- Product: Apache Tomcat Publisher: The Apache Software Foundation Operating System: UNIX variants (UNIX, Linux, OSX) Windows Impact/Access: Denial of Service -- Unknown/Unspecified Resolution: Patch/Upgrade CVE Names: CVE-2016-3092 Original Bulletin: http://mail-archives.apache.org/mod_mbox/tomcat-dev/201606.mbox/%3C6223ece6-2b41-ef4f-22f9-d3481e492832@apache.org%3E - --------------------------BEGIN INCLUDED TEXT-------------------- CVE-2016-3092: Apache Tomcat Denial of Service Severity: Moderate Vendor: The Apache Software Foundation Versions Affected: Apache Tomcat 9.0.0.M1 to 9.0.0M6 Apache Tomcat 8.5.0 to 8.5.2 Apache Tomcat 8.0.0.RC1 to 8.0.35 Apache Tomcat 7.0.0 to 7.0.69 Earlier versions are not affected. Description: CVE-2016-3092 is a denial of service vulnerability that has been corrected in the Apache Commons FileUpload component. It occurred when the length of the multipart boundary was just below the size of the buffer (4096 bytes) used to read the uploaded file. This caused the file upload process to take several orders of magnitude longer than if the boundary length was the typical tens of bytes. Apache Tomcat uses a package renamed copy of Apache Commons FileUpload to implement the file upload requirements of the Servlet specification and was therefore also vulnerable to the denial of service vulnerability. Applications that do not use the File Upload feature introduced in Servlet 3.0 are not affected by the Tomcat aspect of this vulnerability. If those applications use Apache Commons FileUpload, they may still be affected. Mitigation: Users of affected versions should apply one of the following mitigations - - Upgrade to Apache Tomcat 9.0.0.M8 or later (9.0.0.M7 has the fix but was not released) - - Upgrade to Apache Tomcat 8.5.3 or later - - Upgrade to Apache Tomcat 8.0.36 or later - - Upgrade to Apache Tomcat 7.0.70 or later Workaround: The issue may be mitigated by limiting the length of the boundary. Applications could do this with a custom Filter to reject requests that use large boundaries. Tomcat provides the maxHttpHeaderSize attribute on the Connector that can be used to limit the total HTTP header size. Users should be aware that reducing this to 3072 (which should be low enough to protect against this DoS) may cause other issues as applications can require larger headers than this for correct operation, particularly if the application uses relatively large cookie values. Credit: This issue was identified by the TERASOLUNA Framework Development Team at the Software Engineering, Research and Development Headquarters and reported to the ASF via JPCERT. References: http://tomcat.apache.org/security-9.html http://tomcat.apache.org/security-8.html http://tomcat.apache.org/security-7.html - --------------------------END INCLUDED TEXT-------------------- You have received this e-mail bulletin as a result of your organisation's registration with AusCERT. The mailing list you are subscribed to is maintained within your organisation, so if you do not wish to continue receiving these bulletins you should contact your local IT manager. If you do not know who that is, please send an email to auscert@auscert.org.au and we will forward your request to the appropriate person. NOTE: Third Party Rights This security bulletin is provided as a service to AusCERT's members. As AusCERT did not write the document quoted above, AusCERT has had no control over its content. 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Previous advisories and external security bulletins can be retrieved from: http://www.auscert.org.au/render.html?cid=1980 =========================================================================== Australian Computer Emergency Response Team The University of Queensland Brisbane Qld 4072 Internet Email: auscert@auscert.org.au Facsimile: (07) 3365 7031 Telephone: (07) 3365 4417 (International: +61 7 3365 4417) AusCERT personnel answer during Queensland business hours which are GMT+10:00 (AEST). On call after hours for member emergencies only. =========================================================================== -----BEGIN PGP SIGNATURE----- Comment: http://www.auscert.org.au/render.html?it=1967 iQIVAwUBV2ta74x+lLeg9Ub1AQjt/w//WbImPZ09Pw7yd/LeCsginiFjn7+dLPau jodwImn9cLXzoxlFZwfwb9DXsDbQ3sfKG3v5Y4dH7kQ2mP3B9f9p74kIHfrbru/E eKhR5Zn01dSITYAdXDvF1+/OXSI+qwAqT+QHsggv8TAyQyr5JUioF5zQFD2prbVZ hl+NSZbieWWqGRpRZBrWa4oPKzLwmHUbdk8QSzS/a2FtA3p2TZ35nFCvZ9DDaSdX G2/DvoEY3anwgZcMioBZWjpA4sXLMxWW7wjqsh0T7yQErD9VwZSWpoSXkr0wPHL3 ZSbVQx5c4hzcXclkj6NiRYyYFjna6MZvh8rPSG8p42mRzc9b/UVZwxu5KEUUm8MC SaRubMC5pUl10JVq+r2y3qkDPY9Y0ooDUO6RnraE0IVExmzZL2sgpuDFetEGx1En ojedC6Dyzi2z/ko9fYlYhb9jmR4dynMXjqEPpQKB1qbg3ntxJULCDVy80Dcfl/HO bFd6CR1kgaJrISJXQlifTa73ERAqfSSGrfhw0UC785w3ODzi7+8GuQK5XMZ3Cl8q BqEYLwSHT9bo738FFQIHMLj09mlGkrQaHxmB5BRqqGfbdJlEFwCnvqqMzSqBJLnX SKCU2ySl6kxgnXBsXxVpzvSE4TFL2hLNSrbtvKrbtpz/hUK9PQ4SJbO73h33L6kG GTI2w4K7taI= =ggux -----END PGP SIGNATURE-----