CVE Vulnerabilities

CVE-2015-2326

Out-of-bounds Read

Published: Jan 14, 2020 | Modified: Jan 19, 2023
CVSS 3.x
5.5
MEDIUM
Source:
NVD
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
CVSS 2.x
4.3 MEDIUM
AV:N/AC:M/Au:N/C:N/I:N/A:P
RedHat/V2
4.3 MODERATE
AV:N/AC:M/Au:N/C:N/I:N/A:P
RedHat/V3
Ubuntu
LOW

The pcre_compile2 function in PCRE before 8.37 allows context-dependent attackers to compile incorrect code and cause a denial of service (out-of-bounds read) via regular expression with a group containing both a forward referencing subroutine call and a recursive back reference, as demonstrated by ((?+1)(1))/.

Weakness

The product reads data past the end, or before the beginning, of the intended buffer.

Affected Software

Name Vendor Start Version End Version
Pcre Pcre * 8.37 (excluding)
Red Hat Software Collections for Red Hat Enterprise Linux 6 RedHat rh-php56-0:2.3-1.el6 *
Red Hat Software Collections for Red Hat Enterprise Linux 6 RedHat rh-php56-php-0:5.6.25-1.el6 *
Red Hat Software Collections for Red Hat Enterprise Linux 6 RedHat rh-php56-php-pear-1:1.9.5-4.el6 *
Red Hat Software Collections for Red Hat Enterprise Linux 6.7 EUS RedHat rh-php56-0:2.3-1.el6 *
Red Hat Software Collections for Red Hat Enterprise Linux 6.7 EUS RedHat rh-php56-php-0:5.6.25-1.el6 *
Red Hat Software Collections for Red Hat Enterprise Linux 6.7 EUS RedHat rh-php56-php-pear-1:1.9.5-4.el6 *
Red Hat Software Collections for Red Hat Enterprise Linux 7 RedHat rh-php56-0:2.3-1.el7 *
Red Hat Software Collections for Red Hat Enterprise Linux 7 RedHat rh-php56-php-0:5.6.25-1.el7 *
Red Hat Software Collections for Red Hat Enterprise Linux 7 RedHat rh-php56-php-pear-1:1.9.5-4.el7 *
Red Hat Software Collections for Red Hat Enterprise Linux 7.2 EUS RedHat rh-php56-0:2.3-1.el7 *
Red Hat Software Collections for Red Hat Enterprise Linux 7.2 EUS RedHat rh-php56-php-0:5.6.25-1.el7 *
Red Hat Software Collections for Red Hat Enterprise Linux 7.2 EUS RedHat rh-php56-php-pear-1:1.9.5-4.el7 *
Red Hat Software Collections for Red Hat Enterprise Linux 7.3 EUS RedHat rh-php56-0:2.3-1.el7 *
Red Hat Software Collections for Red Hat Enterprise Linux 7.3 EUS RedHat rh-php56-php-0:5.6.25-1.el7 *
Red Hat Software Collections for Red Hat Enterprise Linux 7.3 EUS RedHat rh-php56-php-pear-1:1.9.5-4.el7 *
Pcre3 Ubuntu lucid *
Pcre3 Ubuntu trusty *
Pcre3 Ubuntu trusty/esm *
Pcre3 Ubuntu upstream *
Pcre3 Ubuntu utopic *
Pcre3 Ubuntu vivid *
Pcre3 Ubuntu vivid/stable-phone-overlay *
Pcre3 Ubuntu vivid/ubuntu-core *
Pcre3 Ubuntu wily *

Potential Mitigations

  • Assume all input is malicious. Use an “accept known good” input validation strategy, i.e., use a list of acceptable inputs that strictly conform to specifications. Reject any input that does not strictly conform to specifications, or transform it into something that does.
  • When performing input validation, consider all potentially relevant properties, including length, type of input, the full range of acceptable values, missing or extra inputs, syntax, consistency across related fields, and conformance to business rules. As an example of business rule logic, “boat” may be syntactically valid because it only contains alphanumeric characters, but it is not valid if the input is only expected to contain colors such as “red” or “blue.”
  • Do not rely exclusively on looking for malicious or malformed inputs. This is likely to miss at least one undesirable input, especially if the code’s environment changes. This can give attackers enough room to bypass the intended validation. However, denylists can be useful for detecting potential attacks or determining which inputs are so malformed that they should be rejected outright.
  • To reduce the likelihood of introducing an out-of-bounds read, ensure that you validate and ensure correct calculations for any length argument, buffer size calculation, or offset. Be especially careful of relying on a sentinel (i.e. special character such as NUL) in untrusted inputs.

References