// For flags

CVE-2019-20382

QEMU: vnc: memory leakage upon disconnect

Severity Score

3.5
*CVSS v3.1

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

0
*Multiple Sources

Exploited in Wild

-
*KEV

Decision

-
*SSVC
Descriptions

QEMU 4.1.0 has a memory leak in zrle_compress_data in ui/vnc-enc-zrle.c during a VNC disconnect operation because libz is misused, resulting in a situation where memory allocated in deflateInit2 is not freed in deflateEnd.

QEMU versión 4.1.0, presenta una pérdida de memoria en la función zrle_compress_data en el archivo ui/vnc-enc-zrle.c durante una operación de desconexión de VNC porque libz es usada inapropiadamente, resultando en una situación donde la memoria asignada en deflateInit2 no es liberada en deflateEnd.

A memory leakage flaw was found in the way the VNC display driver of QEMU handled the connection disconnect when ZRLE and Tight encoding are enabled. Two VncState objects are created, and one allocates memory for the Zlib's data object. This allocated memory is not freed upon disconnection, resulting in a memory leak. An attacker able to connect to the VNC server could use this flaw to leak host memory, leading to a potential denial of service.

*Credits: N/A
CVSS Scores
Attack Vector
Adjacent
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
Low
Attack Vector
Adjacent
Attack Complexity
Low
Authentication
Single
Confidentiality
None
Integrity
None
Availability
Partial
* Common Vulnerability Scoring System
SSVC
  • Decision:-
Exploitation
-
Automatable
-
Tech. Impact
-
* Organization's Worst-case Scenario
Timeline
  • 2020-01-20 CVE Reserved
  • 2020-03-05 CVE Published
  • 2023-03-08 EPSS Updated
  • 2024-08-05 CVE Updated
  • ---------- Exploited in Wild
  • ---------- KEV Due Date
  • ---------- First Exploit
CWE
  • CWE-401: Missing Release of Memory after Effective Lifetime
  • CWE-772: Missing Release of Resource after Effective Lifetime
CAPEC
Affected Vendors, Products, and Versions
Vendor Product Version Other Status
Vendor Product Version Other Status <-- --> Vendor Product Version Other Status
Qemu
Search vendor "Qemu"
Qemu
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4.1.0
Search vendor "Qemu" for product "Qemu" and version "4.1.0"
-
Affected
Opensuse
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Leap
Search vendor "Opensuse" for product "Leap"
15.1
Search vendor "Opensuse" for product "Leap" and version "15.1"
-
Affected
Debian
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Debian Linux
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9.0
Search vendor "Debian" for product "Debian Linux" and version "9.0"
-
Affected
Debian
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Debian Linux
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10.0
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-
Affected
Canonical
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Ubuntu Linux
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16.04
Search vendor "Canonical" for product "Ubuntu Linux" and version "16.04"
esm
Affected
Canonical
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Ubuntu Linux
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18.04
Search vendor "Canonical" for product "Ubuntu Linux" and version "18.04"
lts
Affected
Canonical
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Ubuntu Linux
Search vendor "Canonical" for product "Ubuntu Linux"
19.10
Search vendor "Canonical" for product "Ubuntu Linux" and version "19.10"
-
Affected
Canonical
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Ubuntu Linux
Search vendor "Canonical" for product "Ubuntu Linux"
20.04
Search vendor "Canonical" for product "Ubuntu Linux" and version "20.04"
lts
Affected