// For flags

CVE-2019-19126

glibc: LD_PREFER_MAP_32BIT_EXEC not ignored in setuid binaries

Severity Score

3.3
*CVSS v3.1

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

0
*Multiple Sources

Exploited in Wild

-
*KEV

Decision

-
*SSVC
Descriptions

On the x86-64 architecture, the GNU C Library (aka glibc) before 2.31 fails to ignore the LD_PREFER_MAP_32BIT_EXEC environment variable during program execution after a security transition, allowing local attackers to restrict the possible mapping addresses for loaded libraries and thus bypass ASLR for a setuid program.

En la arquitectura de x86-64, la Biblioteca GNU C (también se conoce como glibc) versiones anteriores a 2.31 no omite la variable de entorno de LD_PREFER_MAP_32BIT_EXEC durante la ejecución del programa después de una transición de seguridad, permitiendo a atacantes locales restringir las posibles direcciones de mapeo para las bibliotecas cargadas y así omitir ASLR para un programa setuid

A vulnerability was discovered in glibc where the LD_PREFER_MAP_32BIT_EXEC environment variable is not ignored when running binaries with the setuid flag on x86_64 architectures. This allows an attacker to force system to utilize only half of the memory (making the system think the software is 32-bit only), thus lowering the amount of memory being used with address space layout randomization (ASLR). The highest threat is confidentiality although the complexity of attack is high. The affected application must already have other vulnerabilities for this flaw to be usable.

*Credits: N/A
CVSS Scores
Attack Vector
Local
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
Low
Integrity
None
Availability
None
Attack Vector
Local
Attack Complexity
High
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
Low
Integrity
None
Availability
None
Attack Vector
Local
Attack Complexity
Low
Authentication
None
Confidentiality
Partial
Integrity
None
Availability
None
* Common Vulnerability Scoring System
SSVC
  • Decision:-
Exploitation
-
Automatable
-
Tech. Impact
-
* Organization's Worst-case Scenario
Timeline
  • 2019-11-19 CVE Reserved
  • 2019-11-19 CVE Published
  • 2023-03-08 EPSS Updated
  • 2024-08-05 CVE Updated
  • ---------- Exploited in Wild
  • ---------- KEV Due Date
  • ---------- First Exploit
CWE
  • CWE-20: Improper Input Validation
  • CWE-665: Improper Initialization
CAPEC
Affected Vendors, Products, and Versions
Vendor Product Version Other Status
Vendor Product Version Other Status <-- --> Vendor Product Version Other Status
Gnu
Search vendor "Gnu"
 Glibc
Search vendor "Gnu" for product "Glibc"
 < 2.31
Search vendor "Gnu" for product "Glibc" and version " < 2.31"
x64
Affected
Canonical
Search vendor "Canonical"
 Ubuntu Linux
Search vendor "Canonical" for product "Ubuntu Linux"
 16.04
Search vendor "Canonical" for product "Ubuntu Linux" and version "16.04"
esm
Affected
Canonical
Search vendor "Canonical"
 Ubuntu Linux
Search vendor "Canonical" for product "Ubuntu Linux"
 18.04
Search vendor "Canonical" for product "Ubuntu Linux" and version "18.04"
lts
Affected
Canonical
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 Ubuntu Linux
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 19.10
Search vendor "Canonical" for product "Ubuntu Linux" and version "19.10"
-
Affected
Fedoraproject
Search vendor "Fedoraproject"
 Fedora
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 30
Search vendor "Fedoraproject" for product "Fedora" and version "30"
-
Affected
Fedoraproject
Search vendor "Fedoraproject"
 Fedora
Search vendor "Fedoraproject" for product "Fedora"
 31
Search vendor "Fedoraproject" for product "Fedora" and version "31"
-
Affected
Debian
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 Debian Linux
Search vendor "Debian" for product "Debian Linux"
 10.0
Search vendor "Debian" for product "Debian Linux" and version "10.0"
-
Affected