ID CVE-2016-4356
Summary The append_utf8_value function in the DN decoder (dn.c) in Libksba before 1.3.3 allows remote attackers to cause a denial of service (out-of-bounds read) by clearing the high bit of the byte after invalid utf-8 encoded data.
References
Vulnerable Configurations
  • Libksba Project Libskba 1.3.2
    cpe:2.3:a:libksba_project:libskba:1.3.2
  • Canonical Ubuntu Linux 14.04 LTS (Long-Term Support)
    cpe:2.3:o:canonical:ubuntu_linux:14.04:-:-:-:lts
  • Canonical Ubuntu Linux 12.04 LTS
    cpe:2.3:o:canonical:ubuntu_linux:12.04:-:-:-:lts
CVSS
Base: 5.0 (as of 13-06-2016 - 17:09)
Impact:
Exploitability:
CWE CWE-119
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.
  • Overflow Buffers
    Buffer Overflow attacks target improper or missing bounds checking on buffer operations, typically triggered by input injected by an attacker. As a consequence, an attacker is able to write past the boundaries of allocated buffer regions in memory, causing a program crash or potentially redirection of execution as per the attackers' choice.
  • Client-side Injection-induced Buffer Overflow
    This type of attack exploits a buffer overflow vulnerability in targeted client software through injection of malicious content from a custom-built hostile service.
  • Filter Failure through Buffer Overflow
    In this attack, the idea is to cause an active filter to fail by causing an oversized transaction. An attacker may try to feed overly long input strings to the program in an attempt to overwhelm the filter (by causing a buffer overflow) and hoping that the filter does not fail securely (i.e. the user input is let into the system unfiltered).
  • MIME Conversion
    An attacker exploits a weakness in the MIME conversion routine to cause a buffer overflow and gain control over the mail server machine. The MIME system is designed to allow various different information formats to be interpreted and sent via e-mail. Attack points exist when data are converted to MIME compatible format and back.
  • Overflow Binary Resource File
    An attack of this type exploits a buffer overflow vulnerability in the handling of binary resources. Binary resources may include music files like MP3, image files like JPEG files, and any other binary file. These attacks may pass unnoticed to the client machine through normal usage of files, such as a browser loading a seemingly innocent JPEG file. This can allow the attacker access to the execution stack and execute arbitrary code in the target process. This attack pattern is a variant of standard buffer overflow attacks using an unexpected vector (binary files) to wrap its attack and open up a new attack vector. The attacker is required to either directly serve the binary content to the victim, or place it in a locale like a MP3 sharing application, for the victim to download. The attacker then is notified upon the download or otherwise locates the vulnerability opened up by the buffer overflow.
  • Buffer Overflow via Symbolic Links
    This type of attack leverages the use of symbolic links to cause buffer overflows. An attacker can try to create or manipulate a symbolic link file such that its contents result in out of bounds data. When the target software processes the symbolic link file, it could potentially overflow internal buffers with insufficient bounds checking.
  • Overflow Variables and Tags
    This type of attack leverages the use of tags or variables from a formatted configuration data to cause buffer overflow. The attacker crafts a malicious HTML page or configuration file that includes oversized strings, thus causing an overflow.
  • Buffer Overflow via Parameter Expansion
    In this attack, the target software is given input that the attacker knows will be modified and expanded in size during processing. This attack relies on the target software failing to anticipate that the expanded data may exceed some internal limit, thereby creating a buffer overflow.
  • Buffer Overflow in an API Call
    This attack targets libraries or shared code modules which are vulnerable to buffer overflow attacks. An attacker who has access to an API may try to embed malicious code in the API function call and exploit a buffer overflow vulnerability in the function's implementation. All clients that make use of the code library thus become vulnerable by association. This has a very broad effect on security across a system, usually affecting more than one software process.
  • Buffer Overflow in Local Command-Line Utilities
    This attack targets command-line utilities available in a number of shells. An attacker can leverage a vulnerability found in a command-line utility to escalate privilege to root.
Access
VectorComplexityAuthentication
NETWORK LOW NONE
Impact
ConfidentialityIntegrityAvailability
NONE NONE PARTIAL
nessus via4
  • NASL family FreeBSD Local Security Checks
    NASL id FREEBSD_PKG_A113404810C611E694FA002590263BF5.NASL
    description Martin Prpic, Red Hat Product Security Team, reports : Denial of Service due to stack overflow in src/ber-decoder.c. Integer overflow in the BER decoder src/ber-decoder.c. Integer overflow in the DN decoder src/dn.c.
    last seen 2018-11-24
    modified 2018-11-23
    plugin id 90848
    published 2016-05-03
    reporter Tenable
    source https://www.tenable.com/plugins/index.php?view=single&id=90848
    title FreeBSD : libksba -- local denial of service vulnerabilities (a1134048-10c6-11e6-94fa-002590263bf5)
  • NASL family Ubuntu Local Security Checks
    NASL id UBUNTU_USN-2982-1.NASL
    description Hanno Bock discovered that Libksba incorrectly handled decoding certain BER data. An attacker could use this issue to cause Libksba to crash, resulting in a denial of service. This issue only applied to Ubunt 12.04 LTS and Ubuntu 14.04 LTS. (CVE-2016-4353) Hanno Bock discovered that Libksba incorrectly handled decoding certain BER data. An attacker could use this issue to cause Libksba to crash, resulting in a denial of service, or possibly execute arbitrary code. This issue only applied to Ubunt 12.04 LTS and Ubuntu 14.04 LTS. (CVE-2016-4354, CVE-2016-4355) Hanno Bock discovered that Libksba incorrectly handled incorrect utf-8 strings when decoding certain DN data. An attacker could use this issue to cause Libksba to crash, resulting in a denial of service, or possibly execute arbitrary code. This issue only applied to Ubunt 12.04 LTS and Ubuntu 14.04 LTS. (CVE-2016-4356) Pascal Cuoq discovered that Libksba incorrectly handled incorrect utf-8 strings when decoding certain DN data. An attacker could use this issue to cause Libksba to crash, resulting in a denial of service, or possibly execute arbitrary code. (CVE-2016-4574) Pascal Cuoq discovered that Libksba incorrectly handled decoding certain data. An attacker could use this issue to cause Libksba to crash, resulting in a denial of service. (CVE-2016-4579). Note that Tenable Network Security has extracted the preceding description block directly from the Ubuntu security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.
    last seen 2019-02-21
    modified 2018-12-01
    plugin id 91220
    published 2016-05-18
    reporter Tenable
    source https://www.tenable.com/plugins/index.php?view=single&id=91220
    title Ubuntu 12.04 LTS / 14.04 LTS / 15.10 / 16.04 LTS : libksba vulnerabilities (USN-2982-1)
  • NASL family SuSE Local Security Checks
    NASL id OPENSUSE-2016-624.NASL
    description This update for libksba fixes the following issues : Security issue fixed : - boo#979261: OOB read access bugs remote DoS - CVE-2016-4574: off-by-one OOB read access (incomplete fix for CVE-2016-4356)
    last seen 2019-02-21
    modified 2016-10-13
    plugin id 91289
    published 2016-05-23
    reporter Tenable
    source https://www.tenable.com/plugins/index.php?view=single&id=91289
    title openSUSE Security Update : libksba (openSUSE-2016-624)
refmap via4
confirm http://git.gnupg.org/cgi-bin/gitweb.cgi?p=libksba.git;a=commit;h=243d12fdec66a4360fbb3e307a046b39b5b4ffc3
gentoo GLSA-201604-04
mlist
  • [oss-security] 20160429 CVE request: three issues in libksba
  • [oss-security] 20160429 Re: CVE request: three issues in libksba
  • [oss-security] 20160510 Re: Re: CVE request: three issues in libksba
ubuntu USN-2982-1
Last major update 14-06-2016 - 07:56
Published 13-06-2016 - 15:59
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