CVE-2015-1338 : Detail

CVE-2015-1338

A01-Broken Access Control
0.5%V4
Local
2015-10-01
18h00 +00:00
2015-10-01
17h57 +00:00
CVE.org
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CVE Descriptions

kernel_crashdump in Apport before 2.19 allows local users to cause a denial of service (disk consumption) or possibly gain privileges via a (1) symlink or (2) hard link attack on /var/crash/vmcore.log.

CVE Informations

Related Weaknesses

CWE-ID Weakness Name Source
CWE-59 Improper Link Resolution Before File Access ('Link Following')
The product attempts to access a file based on the filename, but it does not properly prevent that filename from identifying a link or shortcut that resolves to an unintended resource.

Metrics

Metrics Score Severity CVSS Vector Source
V2 7.2 AV:L/AC:L/Au:N/C:C/I:C/A:C nvd@nist.gov

EPSS

EPSS is a scoring model that predicts the likelihood of a vulnerability being exploited.

EPSS Score

The EPSS model produces a probability score between 0 and 1 (0 and 100%). The higher the score, the greater the probability that a vulnerability will be exploited.

EPSS Percentile

The percentile is used to rank CVE according to their EPSS score. For example, a CVE in the 95th percentile according to its EPSS score is more likely to be exploited than 95% of other CVE. Thus, the percentile is used to compare the EPSS score of a CVE with that of other CVE.
EPSS First.org

Exploit information

Exploit Database EDB-ID : 38353

Publication date : 2015-09-28 22h00 +00:00
Author : halfdog
EDB Verified : No

Source: http://www.halfdog.net/Security/2015/ApportKernelCrashdumpFileAccessVulnerabilities/ Problem description: On Ubuntu Vivid Linux distribution apport is used for automated sending of client program crash dumps but also of kernel crash dumps. For kernel crashes, upstart or SysV init invokes the program /usr/share/apport/kernel_crashdump at boot to prepare crash dump files for sending. This action is performed with root privileges. As the crash dump directory /var/crash/ is world writable and kernel_crashdump performs file access in unsafe manner, any local user may trigger a denial of service or escalate to root privileges. If symlink and hardlink protection is enabled (which should be the default for any modern system), only denial of service is possible. Problematic syscall in kernel_crashdump is: open("/var/crash/linux-image-3.19.0-18-generic.0.crash", O_WRONLY|O_CREAT|O_TRUNC|O_LARGEFILE|O_CLOEXEC, 0666) = 30 ... open("/var/crash/vmcore.log", O_RDONLY|O_LARGEFILE|O_CLOEXEC) = 31 Thus the output file is opened unconditionally and without O_EXCL or O_NOFOLLOW. Also opening of input file does not care about links. Proof of Concept: https://gitlab.com/exploit-database/exploitdb-bin-sploits/-/raw/main/bin-sploits/38353.zip

Products Mentioned

Configuraton 0

Apport_project>>Apport >> Version To (including) 2.18.1

Configuraton 0

Canonical>>Ubuntu_linux >> Version 12.04

Canonical>>Ubuntu_linux >> Version 14.04

Canonical>>Ubuntu_linux >> Version 15.04

References

http://www.ubuntu.com/usn/USN-2744-1
Tags : vendor-advisory, x_refsource_UBUNTU
https://www.exploit-db.com/exploits/38353/
Tags : exploit, x_refsource_EXPLOIT-DB
http://seclists.org/fulldisclosure/2015/Sep/101
Tags : mailing-list, x_refsource_FULLDISC