{"id":"CVE-2016-2856","aliases":["DEBIAN-CVE-2016-2856","EUVD-2016-3929","GHSA-2wf2-64hh-9h2m","UBUNTU-CVE-2016-2856","USN-2985-1"],"status":"published","title":"pt_chown in the glibc package before 2.19-18+deb8u4 on Debian jessie; the elibc package before 2...","description":"pt_chown in the glibc package before 2.19-18+deb8u4 on Debian jessie; the elibc package before 2.15-0ubuntu10.14 on Ubuntu 12.04 LTS and before 2.19-0ubuntu6.8 on Ubuntu 14.04 LTS; and the glibc package before 2.21-0ubuntu4.2 on Ubuntu 15.10 and before 2.23-0ubuntu1 on Ubuntu 16.04 LTS and 16.10 lacks a namespace check associated with file-descriptor passing, which allows local users to capture keystrokes and spoof data, and possibly gain privileges, via pts read and write operations, related to debian/sysdeps/linux.mk.  NOTE: this is not considered a vulnerability in the upstream GNU C Library because the upstream documentation has a clear security recommendation against the --enable-pt_chown option.","severity":{"version":"3.0","score":8.4,"vector":"CVSS:3.0/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","level":"high","assessor":"primary","from":"nvd"},"epss":{"day":"2026-11-08","score":0.01029,"percentile":0.63899,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":true,"fix_available":true},"cwes":["CWE-264"],"published":"2016-03-13T00:00:00Z","modified":"2026-09-22T07:01:57Z","exploits":[{"source":"exploitdb","id":"EDB-41760","title":"Ubuntu \u003c 15.10 - PT Chown Arbitrary PTs Access Via User Namespace Privilege Escalation","type":"local","platform":"linux","date":"2016-02-22","url":"https://www.exploit-db.com/exploits/41760"}],"fixes":[{"ecosystem":"Debian:12","package":"glibc","fixed_in":["2.21-1"],"sources":["osv"]},{"ecosystem":"Debian:13","package":"glibc","fixed_in":["2.21-1"],"sources":["osv"]},{"ecosystem":"Debian:14","package":"glibc","fixed_in":["2.21-1"],"sources":["osv"]},{"ecosystem":"Ubuntu:14.04:LTS","package":"eglibc","fixed_in":["2.19-0ubuntu6.8"],"sources":["osv"]}],"affected":[{"source":"osv","ecosystem":"Debian:12","package":"glibc","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2.21-1"}]}]},{"source":"osv","ecosystem":"Debian:13","package":"glibc","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2.21-1"}]}]},{"source":"osv","ecosystem":"Debian:14","package":"glibc","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2.21-1"}]}]},{"source":"osv","ecosystem":"Ubuntu:14.04:LTS","package":"eglibc","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2.19-0ubuntu6.8"}]}],"versions":["2.17-93ubuntu4","2.18-0ubuntu1","2.18-0ubuntu2","2.18-0ubuntu4","2.18-0ubuntu5","2.18-0ubuntu6","2.18-0ubuntu7","2.19-0ubuntu2","2.19-0ubuntu3","2.19-0ubuntu4","2.19-0ubuntu5","2.19-0ubuntu6","2.19-0ubuntu6.1","2.19-0ubuntu6.3","2.19-0ubuntu6.4","2.19-0ubuntu6.5","2.19-0ubuntu6.6","2.19-0ubuntu6.7"]},{"source":"osv","ecosystem":"Ubuntu:14.04:LTS","package":"eglibc","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2.19-0ubuntu6.8"}]}],"versions":["2.17-93ubuntu4","2.18-0ubuntu1","2.18-0ubuntu2","2.18-0ubuntu4","2.18-0ubuntu5","2.18-0ubuntu6","2.18-0ubuntu7","2.19-0ubuntu2","2.19-0ubuntu3","2.19-0ubuntu4","2.19-0ubuntu5","2.19-0ubuntu6","2.19-0ubuntu6.1","2.19-0ubuntu6.3","2.19-0ubuntu6.4","2.19-0ubuntu6.5","2.19-0ubuntu6.6","2.19-0ubuntu6.7"],"bundled":11}],"products":[{"vendor":"canonical","product":"ubuntu_linux"},{"vendor":"debian","product":"debian_linux"}],"references":[{"url":"http://www.halfdog.net/Security/2015/PtChownArbitraryPtsAccessViaUserNamespace/","tags":["x_refsource_MISC","x_transferred","web"]},{"url":"http://anonscm.debian.org/cgit/pkg-glibc/glibc.git/commit/?h=jessie\u0026id=11475c083282c1582c4dd72eecfcb2b7d308c958","tags":["x_refsource_CONFIRM","x_transferred","web","report"]},{"url":"http://www.openwall.com/lists/oss-security/2016/03/07/2","tags":["mailing-list","x_refsource_MLIST","x_transferred","web","report"]},{"url":"http://www.securityfocus.com/bid/84601","tags":["vdb-entry","x_refsource_BID","x_transferred","web"]},{"url":"http://www.ubuntu.com/usn/USN-2985-2","tags":["vendor-advisory","x_refsource_UBUNTU","x_transferred","advisory"]},{"url":"http://people.canonical.com/~ubuntu-security/cve/2016/CVE-2016-2856.html","tags":["x_refsource_CONFIRM","x_transferred","web"]},{"url":"http://anonscm.debian.org/cgit/pkg-glibc/glibc.git/commit/?h=jessie\u0026id=09f7764882a81e13e7b5d87d715412283a6ce403","tags":["x_refsource_CONFIRM","x_transferred","web","report"]},{"url":"http://www.openwall.com/lists/oss-security/2016/02/23/3","tags":["mailing-list","x_refsource_MLIST","x_transferred","web"]},{"url":"http://www.ubuntu.com/usn/USN-2985-1","tags":["vendor-advisory","x_refsource_UBUNTU","x_transferred","advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2016-2856"},{"url":"http://www.halfdog.net/Security/2015/PtChownArbitraryPtsAccessViaUserNamespace"},{"url":"https://github.com/advisories/GHSA-2wf2-64hh-9h2m"},{"url":"https://security-tracker.debian.org/tracker/CVE-2016-2856","tags":["advisory"]},{"url":"https://ubuntu.com/security/CVE-2016-2856","tags":["report"]},{"url":"https://ubuntu.com/security/notices/USN-2985-1","tags":["advisory"]},{"url":"https://www.cve.org/CVERecord?id=CVE-2016-2856","tags":["report"]},{"url":"https://ubuntu.com/security/CVE-2013-2207","tags":["report"]},{"url":"https://ubuntu.com/security/CVE-2014-8121","tags":["report"]},{"url":"https://ubuntu.com/security/CVE-2014-9761","tags":["report"]},{"url":"https://ubuntu.com/security/CVE-2015-1781","tags":["report"]},{"url":"https://ubuntu.com/security/CVE-2015-5277","tags":["report"]},{"url":"https://ubuntu.com/security/CVE-2015-8776","tags":["report"]},{"url":"https://ubuntu.com/security/CVE-2015-8777","tags":["report"]},{"url":"https://ubuntu.com/security/CVE-2015-8778","tags":["report"]},{"url":"https://ubuntu.com/security/CVE-2015-8779","tags":["report"]},{"url":"https://ubuntu.com/security/CVE-2016-3075","tags":["report"]}],"sources":{"cve":[{"id":"CVE-2016-2856","description":"pt_chown in the glibc package before 2.19-18+deb8u4 on Debian jessie; the elibc package before 2.15-0ubuntu10.14 on Ubuntu 12.04 LTS and before 2.19-0ubuntu6.8 on Ubuntu 14.04 LTS; and the glibc package before 2.21-0ubuntu4.2 on Ubuntu 15.10 and before 2.23-0ubuntu1 on Ubuntu 16.04 LTS and 16.10 lacks a namespace check associated with file-descriptor passing, which allows local users to capture keystrokes and spoof data, and possibly gain privileges, via pts read and write operations, related to debian/sysdeps/linux.mk.  NOTE: this is not considered a vulnerability in the upstream GNU C Library because the upstream documentation has a clear security recommendation against the --enable-pt_chown option.","status":"published","published":"2016-03-14T01:00:00Z","modified":"2024-08-05T23:40:13.594Z","updated_at":"2026-11-02T14:33:33.424551Z"}],"euvd":[{"id":"EUVD-2016-3929","description":"pt_chown in the glibc package before 2.19-18+deb8u4 on Debian jessie; the elibc package before 2.15-0ubuntu10.14 on Ubuntu 12.04 LTS and before 2.19-0ubuntu6.8 on Ubuntu 14.04 LTS; and the glibc package before 2.21-0ubuntu4.2 on Ubuntu 15.10 and before 2.23-0ubuntu1 on Ubuntu 16.04 LTS and 16.10 lacks a namespace check associated with file-descriptor passing, which allows local users to capture keystrokes and spoof data, and possibly gain privileges, via pts read and write operations, related to debian/sysdeps/linux.mk.  NOTE: this is not considered a vulnerability in the upstream GNU C Library because the upstream documentation has a clear security recommendation against the --enable-pt_chown option.","status":"published","published":"2016-03-14T01:00:00Z","modified":"2024-08-05T23:40:13Z","updated_at":"2026-11-03T02:22:52.199729Z"}],"ghsa":[{"id":"GHSA-2wf2-64hh-9h2m","title":"pt_chown in the glibc package before 2.19-18+deb8u4 on Debian jessie; the elibc package before 2...","description":"pt_chown in the glibc package before 2.19-18+deb8u4 on Debian jessie; the elibc package before 2.15-0ubuntu10.14 on Ubuntu 12.04 LTS and before 2.19-0ubuntu6.8 on Ubuntu 14.04 LTS; and the glibc package before 2.21-0ubuntu4.2 on Ubuntu 15.10 and before 2.23-0ubuntu1 on Ubuntu 16.04 LTS and 16.10 lacks a namespace check associated with file-descriptor passing, which allows local users to capture keystrokes and spoof data, and possibly gain privileges, via pts read and write operations, related to debian/sysdeps/linux.mk.  NOTE: this is not considered a vulnerability in the upstream GNU C Library because the upstream documentation has a clear security recommendation against the --enable-pt_chown option.","status":"published","published":"2022-05-17T03:42:49Z","modified":"2025-04-12T12:57:49Z","cvss":[{"version":"3.0","score":8.4,"vector":"CVSS:3.0/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","level":"high"}],"updated_at":"2026-11-02T15:01:25.795392Z"}],"nvd":[{"id":"CVE-2016-2856","description":"pt_chown in the glibc package before 2.19-18+deb8u4 on Debian jessie; the elibc package before 2.15-0ubuntu10.14 on Ubuntu 12.04 LTS and before 2.19-0ubuntu6.8 on Ubuntu 14.04 LTS; and the glibc package before 2.21-0ubuntu4.2 on Ubuntu 15.10 and before 2.23-0ubuntu1 on Ubuntu 16.04 LTS and 16.10 lacks a namespace check associated with file-descriptor passing, which allows local users to capture keystrokes and spoof data, and possibly gain privileges, via pts read and write operations, related to debian/sysdeps/linux.mk.  NOTE: this is not considered a vulnerability in the upstream GNU C Library because the upstream documentation has a clear security recommendation against the --enable-pt_chown option.","status":"published","published":"2016-03-14T01:59:04.95Z","modified":"2026-06-17T00:44:36.117Z","cvss":[{"version":"3.0","score":8.4,"vector":"CVSS:3.0/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","level":"high","assessor":"primary"},{"version":"2.0","score":7.2,"vector":"AV:L/AC:L/Au:N/C:C/I:C/A:C","level":"high","assessor":"primary"}],"cwes":["CWE-264"],"updated_at":"2026-11-02T14:03:22.479119Z"}],"osv":[{"id":"CVE-2016-2856","description":"pt_chown in the glibc package before 2.19-18+deb8u4 on Debian jessie; the elibc package before 2.15-0ubuntu10.14 on Ubuntu 12.04 LTS and before 2.19-0ubuntu6.8 on Ubuntu 14.04 LTS; and the glibc package before 2.21-0ubuntu4.2 on Ubuntu 15.10 and before 2.23-0ubuntu1 on Ubuntu 16.04 LTS and 16.10 lacks a namespace check associated with file-descriptor passing, which allows local users to capture keystrokes and spoof data, and possibly gain privileges, via pts read and write operations, related to debian/sysdeps/linux.mk.  NOTE: this is not considered a vulnerability in the upstream GNU C Library because the upstream documentation has a clear security recommendation against the --enable-pt_chown option.","status":"published","published":"2016-03-14T01:59:04.95Z","modified":"2026-03-15T22:06:21.576944Z","cvss":[{"version":"3.0","score":8.4,"vector":"CVSS:3.0/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","level":"high"}],"updated_at":"2026-11-02T15:44:02.114472Z"},{"id":"DEBIAN-CVE-2016-2856","description":"pt_chown in the glibc package before 2.19-18+deb8u4 on Debian jessie; the elibc package before 2.15-0ubuntu10.14 on Ubuntu 12.04 LTS and before 2.19-0ubuntu6.8 on Ubuntu 14.04 LTS; and the glibc package before 2.21-0ubuntu4.2 on Ubuntu 15.10 and before 2.23-0ubuntu1 on Ubuntu 16.04 LTS and 16.10 lacks a namespace check associated with file-descriptor passing, which allows local users to capture keystrokes and spoof data, and possibly gain privileges, via pts read and write operations, related to debian/sysdeps/linux.mk.  NOTE: this is not considered a vulnerability in the upstream GNU C Library because the upstream documentation has a clear security recommendation against the --enable-pt_chown option.","status":"published","published":"2016-03-14T01:59:04.95Z","modified":"2026-09-22T07:01:57.176596159Z","cvss":[{"version":"3.0","score":8.4,"vector":"CVSS:3.0/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","level":"high"}],"updated_at":"2026-11-02T15:45:27.627285Z"},{"id":"UBUNTU-CVE-2016-2856","description":"pt_chown in the glibc package before 2.19-18+deb8u4 on Debian jessie; the elibc package before 2.15-0ubuntu10.14 on Ubuntu 12.04 LTS and before 2.19-0ubuntu6.8 on Ubuntu 14.04 LTS; and the glibc package before 2.21-0ubuntu4.2 on Ubuntu 15.10 and before 2.23-0ubuntu1 on Ubuntu 16.04 LTS and 16.10 lacks a namespace check associated with file-descriptor passing, which allows local users to capture keystrokes and spoof data, and possibly gain privileges, via pts read and write operations, related to debian/sysdeps/linux.mk.  NOTE: this is not considered a vulnerability in the upstream GNU C Library because the upstream documentation has a clear security recommendation against the --enable-pt_chown option.","status":"published","published":"2016-03-13T00:00:00Z","modified":"2026-04-22T10:39:38.625471Z","cvss":[{"version":"3.0","score":8.4,"vector":"CVSS:3.0/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","level":"high"}],"updated_at":"2026-11-02T15:54:11.872222Z"},{"id":"USN-2985-1","title":"eglibc, glibc vulnerabilities","description":"Martin Carpenter discovered that pt_chown in the GNU C Library did not\nproperly check permissions for tty files. A local attacker could use this\nto gain administrative privileges or expose sensitive information.\n(CVE-2013-2207, CVE-2016-2856)\n\nRobin Hack discovered that the Name Service Switch (NSS) implementation in\nthe GNU C Library did not properly manage its file descriptors. An attacker\ncould use this to cause a denial of service (infinite loop).\n(CVE-2014-8121)\n\nJoseph Myers discovered that the GNU C Library did not properly handle long\narguments to functions returning a representation of Not a Number (NaN). An\nattacker could use this to cause a denial of service (stack exhaustion\nleading to an application crash) or possibly execute arbitrary code.\n(CVE-2014-9761)\n\nArjun Shankar discovered that in certain situations the nss_dns code in the\nGNU C Library did not properly account buffer sizes when passed an\nunaligned buffer. An attacker could use this to cause a denial of service\nor possibly execute arbitrary code. (CVE-2015-1781)\n\nSumit Bose and Lukas Slebodnik discovered that the Name Service\nSwitch (NSS) implementation in the GNU C Library did not handle long\nlines in the files databases correctly. A local attacker could use\nthis to cause a denial of service (application crash) or possibly\nexecute arbitrary code. (CVE-2015-5277)\n\nAdam Nielsen discovered that the strftime function in the GNU C Library did\nnot properly handle out-of-range argument data. An attacker could use this\nto cause a denial of service (application crash) or possibly expose\nsensitive information. (CVE-2015-8776)\n\nHector Marco and Ismael Ripoll discovered that the GNU C Library allowed\nthe pointer-guarding protection mechanism to be disabled by honoring the\nLD_POINTER_GUARD environment variable across privilege boundaries. A local\nattacker could use this to exploit an existing vulnerability more easily.\n(CVE-2015-8777)\n\nSzabolcs Nagy discovered that the hcreate functions in the GNU C Library\ndid not properly check its size argument, leading to an integer overflow.\nAn attacker could use to cause a denial of service (application crash) or\npossibly execute arbitrary code. (CVE-2015-8778)\n\nMaksymilian Arciemowicz discovered a stack-based buffer overflow in the\ncatopen function in the GNU C Library when handling long catalog names. An\nattacker could use this to cause a denial of service (application crash) or\npossibly execute arbitrary code. (CVE-2015-8779)\n\nFlorian Weimer discovered that the getnetbyname implementation in the GNU C\nLibrary did not properly handle long names passed as arguments. An attacker\ncould use to cause a denial of service (stack exhaustion leading to an\napplication crash). (CVE-2016-3075)\n","status":"published","published":"2016-05-25T20:22:47Z","modified":"2026-04-27T15:17:30.767227083Z","updated_at":"2026-11-02T16:58:10.303275Z"}]}}