Protect yourself against future threats.
-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 =========================================================================== AUSCERT Security Bulletin ASB-2016.0022 PuTTY vulnerability vuln-pscp-sink-sscanf 7 March 2016 =========================================================================== AusCERT Security Bulletin Summary --------------------------------- Product: PuTTY Operating System: Windows Impact/Access: Execute Arbitrary Code/Commands -- Remote with User Interaction Denial of Service -- Remote with User Interaction Resolution: Patch/Upgrade CVE Names: CVE-2016-2563 Member content until: Wednesday, April 6 2016 OVERVIEW A vulnerability has been identified in PuTTY prior to version 0.67. [1] IMPACT The vendor has provided the following details regarding the vulnerability: "Prior to any download in the SCP sink protocol, the server sends a line of text consisting of an octal number encoding Unix file permissions, a decimal number encoding the file size, and the file name. Since the file size can exceed 232 bytes, and in some compilation configurations of PuTTY the host platform's largest integer type is only 32 bits wide, PuTTY extracts the decimal file size into a temporary string variable to send to its own 64-bit decimal decoding function. Unfortunately, that extraction was done carelessly, using a sscanf with no length limit, permitting a buffer overrun." [1] MITIGATION The vendor advises updating to the latest version will fix this issue. [1] REFERENCES [1] PuTTY vulnerability vuln-pscp-sink-sscanf http://www.chiark.greenend.org.uk/~sgtatham/putty/wishlist/vuln-pscp-sink-sscanf.html AusCERT has made every effort to ensure that the information contained in this document is accurate. However, the decision to use the information described is the responsibility of each user or organisation. The decision to follow or act on information or advice contained in this security bulletin is the responsibility of each user or organisation, and should be considered in accordance with your organisation's site policies and procedures. AusCERT takes no responsibility for consequences which may arise from following or acting on information or advice contained in this security bulletin. =========================================================================== 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 iQIVAwUBVtzVFn6ZAP0PgtI9AQL6DA/9HiDPsrGT5+YMkemUOuKWL12UArcl4wQu /tAZP0wpdiPoMqeeZBGAkge73PFYW/BADzzdCJdknO2+Sum/POifpOiS+A5Rgl0O mYRZkJzWj0ihgdmtO9/M6QUKMwzFqvPy2sUocTkmcNsD8uiPcUGexXeIdybv466v bSm6Qvj4etSOIwtspHAClGRchlbgvCS1/PEgmpbNe8zUqLb/fDSmtw41iltfEkfO kLPlgCZM9/wiuGCepD2iuzWlbbd8qqy2TAnlhbrRCCPS4ku7HlX/ldH735YBXMtG bk1ZOnuUFLLwu/V0dMMqzp41qP/KwSgGAODxuTtXETQlxHiHDQE92hC7lhE2Odws m7XFxF7QYs1ylXfXV2mQm8LCv2DERgyYrfzPtvyJSNqmo5e+EMTlUM8pOC43akBh h+NSbhhi5XNXRvUyIZQD7hY1hoUNV+7XVncngAkcIdLQrXkL/3dLNtypDZmoN9cC JIyLVWsAhTP0n2TvHgLwDyqxPW2M8kdt7xWrOw4r0/Obc7yinyzqQjnXZpZHfJig CDeXteZm/XRHwMrOyIE2AZdqI177Jx3d7+6gRDmX391cYmex8uFOmJusuE7H0RgN YGozEF0EK/mrI0iye4vWmJ+A0XNl4jQp6mRcPL8cQ8fA+7/i+31Late18JlwaSeB QA7WyZqSGKQ= =mLiK -----END PGP SIGNATURE-----