// For flags

CVE-2023-3138

libX11: InitExt.c can overwrite unintended portions of the Display structure if the extension request leads to a buffer overflow

Severity Score

7.5
*CVSS v3.1

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

0
*Multiple Sources

Exploited in Wild

-
*KEV

Decision

-
*SSVC
Descriptions

A vulnerability was found in libX11. The security flaw occurs because the functions in src/InitExt.c in libX11 do not check that the values provided for the Request, Event, or Error IDs are within the bounds of the arrays that those functions write to, using those IDs as array indexes. They trust that they were called with values provided by an Xserver adhering to the bounds specified in the X11 protocol, as all X servers provided by X.Org do. As the protocol only specifies a single byte for these values, an out-of-bounds value provided by a malicious server (or a malicious proxy-in-the-middle) can only overwrite other portions of the Display structure and not write outside the bounds of the Display structure itself, possibly causing the client to crash with this memory corruption.

*Credits: N/A
CVSS Scores
Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High
Attack Vector
Network
Attack Complexity
Low
Privileges Required
Low
User Interaction
Required
Scope
Unchanged
Confidentiality
None
Integrity
High
Availability
High
* Common Vulnerability Scoring System
SSVC
  • Decision:-
Exploitation
-
Automatable
-
Tech. Impact
-
* Organization's Worst-case Scenario
Timeline
  • 2023-06-07 CVE Reserved
  • 2023-06-16 CVE Published
  • 2024-08-02 CVE Updated
  • 2024-10-02 EPSS Updated
  • ---------- Exploited in Wild
  • ---------- KEV Due Date
  • ---------- First Exploit
CWE
  • CWE-119: Improper Restriction of Operations within the Bounds of a Memory Buffer
  • CWE-787: Out-of-bounds Write
CAPEC
Affected Vendors, Products, and Versions
Vendor Product Version Other Status
Vendor Product Version Other Status <-- --> Vendor Product Version Other Status
X.org
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Libx11
Search vendor "X.org" for product "Libx11"
< 1.8.6
Search vendor "X.org" for product "Libx11" and version " < 1.8.6"
-
Affected
Redhat
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Enterprise Linux
Search vendor "Redhat" for product "Enterprise Linux"
8.0
Search vendor "Redhat" for product "Enterprise Linux" and version "8.0"
-
Affected
Redhat
Search vendor "Redhat"
Enterprise Linux
Search vendor "Redhat" for product "Enterprise Linux"
9.0
Search vendor "Redhat" for product "Enterprise Linux" and version "9.0"
-
Affected