--- title: "CVE-2011-2495\n | Ubuntu" description: Ubuntu is an open source software operating system that runs from the desktop, to the cloud, to all your internet connected things. url: https://ubuntu.com/security/CVE-2011-2495?format=md keywords: index, follow --- # CVE-2011-2495 Publication date 3 October 2011 Last updated 4 July 2026 --- Ubuntu priority **Medium** [Why this priority?](https://ubuntu.com/security/cves/about#priority ) Toggle side navigation ## Description fs/proc/base.c in the Linux kernel before 2.6.39.4 does not properly restrict access to /proc/#####/io files, which allows local users to obtain sensitive I/O statistics by polling a file, as demonstrated by discovering the length of another user's password. ### From the Ubuntu Security Team Vasiliy Kulikov discovered that /proc/PID/io did not enforce access restrictions. A local attacker could exploit this to read certain information, leading to a loss of privacy. ## Status Show unmaintained releases | Package | Ubuntu Release | Status | | --- | --- | --- | | linux | 11.10 oneiric | Not affected | | 11.04 natty | Fixed 2.6.38-13.52 | | 10.10 maverick | Fixed 2.6.35-30.61 | | 10.04 LTS lucid | Fixed 2.6.32-35.78 | | 8.04 LTS hardy | Fixed 2.6.24-29.95 | | linux-ec2 | 11.10 oneiric | Not in release | | 11.04 natty | Not in release | | 10.10 maverick | Ignored end of life | | 10.04 LTS lucid | Fixed 2.6.32-319.39 | | 8.04 LTS hardy | Not in release | | linux-fsl-imx51 | 11.10 oneiric | Not in release | | 11.04 natty | Not in release | | 10.10 maverick | Not in release | | 10.04 LTS lucid | Fixed 2.6.31-611.29 | | 8.04 LTS hardy | Not in release | | linux-lts-backport-maverick | 11.10 oneiric | Not in release | | 11.04 natty | Not in release | | 10.10 maverick | Not in release | | 10.04 LTS lucid | Fixed 2.6.35-30.61~lucid1 | | 8.04 LTS hardy | Not in release | | linux-lts-backport-natty | 11.10 oneiric | Not in release | | 11.04 natty | Not in release | | 10.10 maverick | Not in release | | 10.04 LTS lucid | Fixed 2.6.38-13.52~lucid1 | | 8.04 LTS hardy | Not in release | | linux-lts-backport-oneiric | 11.10 oneiric | Not in release | | 11.04 natty | Not in release | | 10.10 maverick | Not in release | | 10.04 LTS lucid | Not affected | | 8.04 LTS hardy | Not in release | | linux-mvl-dove | 11.10 oneiric | Not in release | | 11.04 natty | Not in release | | 10.10 maverick | Fixed 2.6.32-419.37 | | 10.04 LTS lucid | Fixed 2.6.32-219.37 | | 8.04 LTS hardy | Not in release | | linux-ti-omap4 | 11.10 oneiric | Not affected | | 11.04 natty | Fixed 2.6.38-1209.17 | | 10.10 maverick | Fixed 2.6.35-903.26 | | 10.04 LTS lucid | Not in release | | 8.04 LTS hardy | Not in release | --- * [How can I get the fixes?](https://ubuntu.com/security/cves/about#security) * [What do statuses mean?](https://ubuntu.com/security/cves/about#statuses) * [Patch details](https://ubuntu.com/security/CVE-2011-2495?format=md#patch-details) ### Patch details For informational purposes only. We recommend not to cherry-pick updates. [How can I get the fixes?](https://ubuntu.com/security/cves/about#security) | Package | Patch details | | --- | --- | | linux | * Introduced by [1da177e](https://git.kernel.org/linus/1da177e4c3f41524e886b7f1b8a0c1fc7321cac2), fixed by [1d1221f](https://git.kernel.org/linus/1d1221f375c94ef961ba8574ac4f85c8870ddd51) * Introduced by [d84f4f9](https://git.kernel.org/linus/d84f4f992cbd76e8f39c488cf0c5d123843923b1), fixed by [293eb1e](https://git.kernel.org/linus/293eb1e7772b25a93647c798c7b89bf26c2da2e0) | ## References * [MITRE](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2011-2495) * [NVD](https://nvd.nist.gov/vuln/detail/CVE-2011-2495) * [Launchpad](https://launchpad.net/bugs/cve/CVE-2011-2495) * [Debian](https://security-tracker.debian.org/tracker/CVE-2011-2495) ### Related Ubuntu Security Notices (USN) + [USN-1241-1](https://usn.ubuntu.com/USN-1241-1) + Linux kernel (i.MX51) vulnerabilities + 25 October 2011 + [USN-1243-1](https://usn.ubuntu.com/USN-1243-1) + Linux kernel vulnerabilities + 25 October 2011 + [USN-1253-1](https://usn.ubuntu.com/USN-1253-1) + Linux kernel vulnerabilities + 8 November 2011 + [USN-1239-1](https://usn.ubuntu.com/USN-1239-1) + Linux kernel (EC2) vulnerabilities + 25 October 2011 + [USN-1281-1](https://usn.ubuntu.com/USN-1281-1) + Linux (OMAP4) vulnerabilities + 24 November 2011 + [USN-1285-1](https://usn.ubuntu.com/USN-1285-1) + Linux kernel vulnerabilities + 29 November 2011 + [USN-1279-1](https://usn.ubuntu.com/USN-1279-1) + Linux (Natty backport) vulnerabilities + 24 November 2011 + [USN-1236-1](https://usn.ubuntu.com/USN-1236-1) + Linux kernel vulnerabilities + 20 October 2011 + [USN-1244-1](https://usn.ubuntu.com/USN-1244-1) + Linux kernel (OMAP4) vulnerabilities + 25 October 2011 + [USN-1240-1](https://usn.ubuntu.com/USN-1240-1) + Linux kernel (Marvell DOVE) vulnerabilities + 25 October 2011 + [USN-1245-1](https://usn.ubuntu.com/USN-1245-1) + Linux kernel (Marvell DOVE) vulnerabilities + 25 October 2011 + [USN-1242-1](https://usn.ubuntu.com/USN-1242-1) + Linux kernel (Maverick backport) vulnerabilities + 25 October 2011 ### Other references * * *