Vulnerabilities > CVE-2015-20109 - Classic Buffer Overflow vulnerability in GNU Glibc

047910
CVSS 5.5 - MEDIUM
Attack vector
LOCAL
Attack complexity
LOW
Privileges required
NONE
Confidentiality impact
NONE
Integrity impact
NONE
Availability impact
HIGH
local
low complexity
gnu
CWE-120

Summary

end_pattern (called from internal_fnmatch) in the GNU C Library (aka glibc or libc6) before 2.22 might allow context-dependent attackers to cause a denial of service (application crash), as demonstrated by use of the fnmatch library function with the **(!() pattern. NOTE: this is not the same as CVE-2015-8984; also, some Linux distributions have fixed CVE-2015-8984 but have not fixed this additional fnmatch issue.

Vulnerable Configurations

Part Description Count
Application
Gnu
113

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.
  • 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.