Vulnerabilities > CVE-2011-0017 - Improper Input Validation vulnerability in Exim
Attack vector
LOCAL Attack complexity
MEDIUM Privileges required
NONE Confidentiality impact
COMPLETE Integrity impact
COMPLETE Availability impact
COMPLETE Summary
The open_log function in log.c in Exim 4.72 and earlier does not check the return value from (1) setuid or (2) setgid system calls, which allows local users to append log data to arbitrary files via a symlink attack.
Vulnerable Configurations
Common Weakness Enumeration (CWE)
Common Attack Pattern Enumeration and Classification (CAPEC)
- Buffer Overflow via Environment Variables This attack pattern involves causing a buffer overflow through manipulation of environment variables. Once the attacker finds that they can modify an environment variable, they may try to overflow associated buffers. This attack leverages implicit trust often placed in environment variables.
- Server Side Include (SSI) Injection An attacker can use Server Side Include (SSI) Injection to send code to a web application that then gets executed by the web server. Doing so enables the attacker to achieve similar results to Cross Site Scripting, viz., arbitrary code execution and information disclosure, albeit on a more limited scale, since the SSI directives are nowhere near as powerful as a full-fledged scripting language. Nonetheless, the attacker can conveniently gain access to sensitive files, such as password files, and execute shell commands.
- Cross Zone Scripting An attacker is able to cause a victim to load content into their web-browser that bypasses security zone controls and gain access to increased privileges to execute scripting code or other web objects such as unsigned ActiveX controls or applets. This is a privilege elevation attack targeted at zone-based web-browser security. In a zone-based model, pages belong to one of a set of zones corresponding to the level of privilege assigned to that page. Pages in an untrusted zone would have a lesser level of access to the system and/or be restricted in the types of executable content it was allowed to invoke. In a cross-zone scripting attack, a page that should be assigned to a less privileged zone is granted the privileges of a more trusted zone. This can be accomplished by exploiting bugs in the browser, exploiting incorrect configuration in the zone controls, through a cross-site scripting attack that causes the attackers' content to be treated as coming from a more trusted page, or by leveraging some piece of system functionality that is accessible from both the trusted and less trusted zone. This attack differs from "Restful Privilege Escalation" in that the latter correlates to the inadequate securing of RESTful access methods (such as HTTP DELETE) on the server, while cross-zone scripting attacks the concept of security zones as implemented by a browser.
- Cross Site Scripting through Log Files An attacker may leverage a system weakness where logs are susceptible to log injection to insert scripts into the system's logs. If these logs are later viewed by an administrator through a thin administrative interface and the log data is not properly HTML encoded before being written to the page, the attackers' scripts stored in the log will be executed in the administrative interface with potentially serious consequences. This attack pattern is really a combination of two other attack patterns: log injection and stored cross site scripting.
- Command Line Execution through SQL Injection An attacker uses standard SQL injection methods to inject data into the command line for execution. This could be done directly through misuse of directives such as MSSQL_xp_cmdshell or indirectly through injection of data into the database that would be interpreted as shell commands. Sometime later, an unscrupulous backend application (or could be part of the functionality of the same application) fetches the injected data stored in the database and uses this data as command line arguments without performing proper validation. The malicious data escapes that data plane by spawning new commands to be executed on the host.
Nessus
NASL family SuSE Local Security Checks NASL id SUSE_11_2_EXIM-110207.NASL description Exim was updated to verify the return value of the setuid/setgid calls now. (CVE-2011-0017: CVSS v2 Base Score: 6.9 (AV:L/AC:M/Au:N/C:C/I:C/A:C): Link Following (CWE-59)) last seen 2020-06-01 modified 2020-06-02 plugin id 53716 published 2011-05-05 reporter This script is Copyright (C) 2011-2019 and is owned by Tenable, Inc. or an Affiliate thereof. source https://www.tenable.com/plugins/nessus/53716 title openSUSE Security Update : exim (openSUSE-SU-2011:0105-1) code #%NASL_MIN_LEVEL 80502 # # (C) Tenable Network Security, Inc. # # The descriptive text and package checks in this plugin were # extracted from openSUSE Security Update exim-3922. # # The text description of this plugin is (C) SUSE LLC. # include("compat.inc"); if (description) { script_id(53716); script_version("1.5"); script_cvs_date("Date: 2019/10/25 13:36:40"); script_cve_id("CVE-2011-0017"); script_name(english:"openSUSE Security Update : exim (openSUSE-SU-2011:0105-1)"); script_summary(english:"Check for the exim-3922 patch"); script_set_attribute( attribute:"synopsis", value:"The remote openSUSE host is missing a security update." ); script_set_attribute( attribute:"description", value: "Exim was updated to verify the return value of the setuid/setgid calls now. (CVE-2011-0017: CVSS v2 Base Score: 6.9 (AV:L/AC:M/Au:N/C:C/I:C/A:C): Link Following (CWE-59))" ); script_set_attribute( attribute:"see_also", value:"https://bugzilla.novell.com/show_bug.cgi?id=668599" ); script_set_attribute( attribute:"see_also", value:"https://lists.opensuse.org/opensuse-updates/2011-02/msg00005.html" ); script_set_attribute(attribute:"solution", value:"Update the affected exim packages."); script_set_cvss_base_vector("CVSS2#AV:L/AC:M/Au:N/C:C/I:C/A:C"); script_set_attribute(attribute:"plugin_type", value:"local"); script_set_attribute(attribute:"cpe", value:"p-cpe:/a:novell:opensuse:exim"); script_set_attribute(attribute:"cpe", value:"p-cpe:/a:novell:opensuse:eximon"); script_set_attribute(attribute:"cpe", value:"p-cpe:/a:novell:opensuse:eximstats-html"); script_set_attribute(attribute:"cpe", value:"cpe:/o:novell:opensuse:11.2"); script_set_attribute(attribute:"patch_publication_date", value:"2011/02/07"); script_set_attribute(attribute:"plugin_publication_date", value:"2011/05/05"); script_end_attributes(); script_category(ACT_GATHER_INFO); script_copyright(english:"This script is Copyright (C) 2011-2019 and is owned by Tenable, Inc. or an Affiliate thereof."); script_family(english:"SuSE Local Security Checks"); script_dependencies("ssh_get_info.nasl"); script_require_keys("Host/local_checks_enabled", "Host/SuSE/release", "Host/SuSE/rpm-list", "Host/cpu"); exit(0); } include("audit.inc"); include("global_settings.inc"); include("rpm.inc"); if (!get_kb_item("Host/local_checks_enabled")) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED); release = get_kb_item("Host/SuSE/release"); if (isnull(release) || release =~ "^(SLED|SLES)") audit(AUDIT_OS_NOT, "openSUSE"); if (release !~ "^(SUSE11\.2)$") audit(AUDIT_OS_RELEASE_NOT, "openSUSE", "11.2", release); if (!get_kb_item("Host/SuSE/rpm-list")) audit(AUDIT_PACKAGE_LIST_MISSING); ourarch = get_kb_item("Host/cpu"); if (!ourarch) audit(AUDIT_UNKNOWN_ARCH); if (ourarch !~ "^(i586|i686|x86_64)$") audit(AUDIT_ARCH_NOT, "i586 / i686 / x86_64", ourarch); flag = 0; if ( rpm_check(release:"SUSE11.2", reference:"exim-4.69-72.8.1") ) flag++; if ( rpm_check(release:"SUSE11.2", reference:"eximon-4.69-72.8.1") ) flag++; if ( rpm_check(release:"SUSE11.2", reference:"eximstats-html-4.69-72.8.1") ) flag++; if (flag) { if (report_verbosity > 0) security_warning(port:0, extra:rpm_report_get()); else security_warning(0); exit(0); } else { tested = pkg_tests_get(); if (tested) audit(AUDIT_PACKAGE_NOT_AFFECTED, tested); else audit(AUDIT_PACKAGE_NOT_INSTALLED, "exim"); }
NASL family Debian Local Security Checks NASL id DEBIAN_DSA-2154.NASL description A design flaw (CVE-2010-4345 ) in exim4 allowed the local Debian-exim user to obtain root privileges by specifying an alternate configuration file using the -C option or by using the macro override facility (-D option). Unfortunately, fixing this vulnerability is not possible without some changes in exim4 last seen 2020-03-17 modified 2011-01-31 plugin id 51819 published 2011-01-31 reporter This script is Copyright (C) 2011-2020 and is owned by Tenable, Inc. or an Affiliate thereof. source https://www.tenable.com/plugins/nessus/51819 title Debian DSA-2154-1 : exim4 - privilege escalation NASL family SuSE Local Security Checks NASL id SUSE_11_3_EXIM-110207.NASL description Exim was updated to verify the return value of the setuid/setgid calls now. (CVE-2011-0017: CVSS v2 Base Score: 6.9 (AV:L/AC:M/Au:N/C:C/I:C/A:C): Link Following (CWE-59)) last seen 2020-06-01 modified 2020-06-02 plugin id 75482 published 2014-06-13 reporter This script is Copyright (C) 2014-2019 and is owned by Tenable, Inc. or an Affiliate thereof. source https://www.tenable.com/plugins/nessus/75482 title openSUSE Security Update : exim (openSUSE-SU-2011:0105-1) NASL family Ubuntu Local Security Checks NASL id UBUNTU_USN-1060-1.NASL description It was discovered that Exim contained a design flaw in the way it processed alternate configuration files. An attacker that obtained privileges of the last seen 2020-06-01 modified 2020-06-02 plugin id 51954 published 2011-02-11 reporter Ubuntu Security Notice (C) 2011-2019 Canonical, Inc. / NASL script (C) 2011-2019 and is owned by Tenable, Inc. or an Affiliate thereof. source https://www.tenable.com/plugins/nessus/51954 title Ubuntu 6.06 LTS / 8.04 LTS / 9.10 / 10.04 LTS / 10.10 : exim4 vulnerabilities (USN-1060-1) NASL family FreeBSD Local Security Checks NASL id FREEBSD_PKG_44CCFAB0356411E08E810022190034C0.NASL description exim.org reports : CVE-2011-0017 - check return value of setuid/setgid. This is a privilege escalation vulnerability whereby the Exim run-time user can cause root to append content of the attacker last seen 2020-06-01 modified 2020-06-02 plugin id 51963 published 2011-02-14 reporter This script is Copyright (C) 2011-2019 and is owned by Tenable, Inc. or an Affiliate thereof. source https://www.tenable.com/plugins/nessus/51963 title FreeBSD : exim -- local privilege escalation (44ccfab0-3564-11e0-8e81-0022190034c0) NASL family SMTP problems NASL id EXIM_4_74.NASL description The remote host is running Exim, a message transfer agent. According to the version number in its banner, the installed version of Exim is earlier than 4.74 and thus potentially affected by a local privilege escalation vulnerability. If the remote host is running Linux, attackers can exploit this issue to append arbitrary data to files through symbolic link attacks. Successfully exploiting this issue allows local attackers with last seen 2020-06-01 modified 2020-06-02 plugin id 51861 published 2011-02-03 reporter This script is Copyright (C) 2011-2018 Tenable Network Security, Inc. source https://www.tenable.com/plugins/nessus/51861 title Exim < 4.74 Local Privilege Escalation NASL family Gentoo Local Security Checks NASL id GENTOO_GLSA-201401-32.NASL description The remote host is affected by the vulnerability described in GLSA-201401-32 (Exim: Multiple vulnerabilities) Multiple vulnerabilities have been discovered in Exim. Please review the CVE identifiers referenced below for details. Impact : A remote attacker could possibly execute arbitrary code with root privileges, or cause a Denial of Service condition. Workaround : There is no known workaround at this time. last seen 2020-06-01 modified 2020-06-02 plugin id 72159 published 2014-01-28 reporter This script is Copyright (C) 2014-2018 Tenable Network Security, Inc. source https://www.tenable.com/plugins/nessus/72159 title GLSA-201401-32 : Exim: Multiple vulnerabilities
References
- ftp://ftp.exim.org/pub/exim/ChangeLogs/ChangeLog-4.74
- http://lists.exim.org/lurker/message/20110126.034702.4d69c278.en.html
- http://lists.opensuse.org/opensuse-security-announce/2011-02/msg00004.html
- http://osvdb.org/70696
- http://secunia.com/advisories/43101
- http://secunia.com/advisories/43128
- http://secunia.com/advisories/43243
- http://www.debian.org/security/2011/dsa-2154
- http://www.securityfocus.com/bid/46065
- http://www.ubuntu.com/usn/USN-1060-1
- http://www.vupen.com/english/advisories/2011/0224
- http://www.vupen.com/english/advisories/2011/0245
- http://www.vupen.com/english/advisories/2011/0364
- http://www.vupen.com/english/advisories/2011/0464
- https://exchange.xforce.ibmcloud.com/vulnerabilities/65028