--- title: "CVE-2011-3363\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-2011-3363?format=md keywords: index, follow --- # CVE-2011-3363 Publication date 3 October 2011 Last updated 4 July 2026 --- Ubuntu priority **Medium** [Why this priority?](https://ubuntu.com/security/cves/about#priority ) ## Cvss 3 Severity Score **6.5 · Medium** [Score breakdown](https://ubuntu.com/security/CVE-2011-3363?format=md#impact-score) Toggle side navigation ## Description The setup\_cifs\_sb function in fs/cifs/connect.c in the Linux kernel before 2.6.39 does not properly handle DFS referrals, which allows remote CIFS servers to cause a denial of service (system crash) by placing a referral at the root of a share. ### From the Ubuntu Security Team Yogesh Sharma discovered that CIFS did not correctly handle UNCs that had no prefixpaths. A local attacker with access to a CIFS partition could exploit this to crash the system, leading to a denial of service. [Read the notes from the security team](https://ubuntu.com/security/CVE-2011-3363?format=md#notes) ## Status Show unmaintained releases | Package | Ubuntu Release | Status | | --- | --- | --- | | linux | 11.10 oneiric | Not affected | | 11.04 natty | Fixed 2.6.38-10.44 | | 10.10 maverick | Fixed 2.6.35-30.61 | | 10.04 LTS lucid | Fixed 2.6.32-33.64 | | 8.04 LTS hardy | Not affected | | 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 2.6.32-317.32 | | 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 2.6.38-10.44~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 2.6.32-417.34 | | 10.04 LTS lucid | Fixed 2.6.32-217.34 | | 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-2011-3363?format=md#patch-details) ## Notes --- ### [mdeslaur](https://launchpad.net/~mdeslaur) from oss-security: "If you have this, you might also want cifs: add fallback in is\_path\_accessible for old servers 221d1d797202984cb874e3ed9f1388593d34ee22" ### 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 [e4cce94](https://git.kernel.org/linus/e4cce94c9c8797b08faf6a79396df4d175e377fa), fixed by [7094564](https://git.kernel.org/linus/70945643722ffeac779d2529a348f99567fa5c33) * Introduced by [e4cce94](https://git.kernel.org/linus/e4cce94c9c8797b08faf6a79396df4d175e377fa), fixed by [221d1d7](https://git.kernel.org/linus/221d1d797202984cb874e3ed9f1388593d34ee22) | ## Severity score breakdown CVSS version: CVSS v3.0 **Base score** 6.5 · Medium * Base metrics | Parameter | Value | | --- | --- | | Attack vector | Adjacent | | Attack complexity | Low | | Privileges required | None | | User interaction | None | | Scope | Unchanged | | Confidentiality impact | None | | Integrity impact | None | | Availability impact | High | * Scores | Parameter | Value | | --- | --- | | Base score | 6.5 · Medium | | Exploitability score | - | | Impact score | - | **Vector:** CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H ## References * [MITRE](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2011-3363) * [NVD](https://nvd.nist.gov/vuln/detail/CVE-2011-3363) * [Launchpad](https://launchpad.net/bugs/cve/CVE-2011-3363) * [Debian](https://security-tracker.debian.org/tracker/CVE-2011-3363) ### 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-1281-1](https://usn.ubuntu.com/USN-1281-1) + Linux (OMAP4) vulnerabilities + 24 November 2011 + [USN-1244-1](https://usn.ubuntu.com/USN-1244-1) + Linux kernel (OMAP4) vulnerabilities + 25 October 2011 + [USN-1168-1](https://usn.ubuntu.com/USN-1168-1) + Linux kernel vulnerabilities + 15 July 2011 + [USN-1162-1](https://usn.ubuntu.com/USN-1162-1) + Linux kernel vulnerabilities (Marvell Dove) + 29 June 2011 + [USN-1167-1](https://usn.ubuntu.com/USN-1167-1) + Linux kernel vulnerabilities + 13 July 2011 + [USN-1256-1](https://usn.ubuntu.com/USN-1256-1) + Linux kernel (Natty backport) vulnerabilities + 9 November 2011 + [USN-1242-1](https://usn.ubuntu.com/USN-1242-1) + Linux kernel (Maverick backport) vulnerabilities + 25 October 2011 + [USN-1161-1](https://usn.ubuntu.com/USN-1161-1) + Linux kernel vulnerabilities (EC2) + 13 July 2011 + [USN-1159-1](https://usn.ubuntu.com/USN-1159-1) + Linux kernel vulnerabilities (Marvell Dove) + 13 July 2011 ### Other references *