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Vulnerability details: VCID-y4mh-xhvx-yubd
Vulnerability ID VCID-y4mh-xhvx-yubd
Aliases CVE-2020-9850
Summary Multiple vulnerabilities have been found in WebKitGTK+, the worst of which could result in the arbitrary execution of code.
Status Published
Exploitability 2.0
Weighted Severity 9.0
Risk 10.0
Affected and Fixed Packages Package Details
Weaknesses (1)
Data source Metasploit
Description This module exploits an incorrect side-effect modeling of the 'in' operator. The DFG compiler assumes that the 'in' operator is side-effect free, however the <embed> element with the PDF plugin provides a callback that can trigger side-effects leading to type confusion (CVE-2020-9850). The type confusion can be used as addrof and fakeobj primitives that then lead to arbitrary read/write of memory. These primitives allow us to write shellcode into a JIT region (RWX memory) containing the next stage of the exploit. The next stage uses CVE-2020-9856 to exploit a heap overflow in CVM Server, and extracts a macOS application containing our payload into /var/db/CVMS. The payload can then be opened with CVE-2020-9801, executing the payload as a user but without sandbox restrictions.
Note
Reliability:
  - repeatable-session
SideEffects:
  - ioc-in-logs
Stability:
  - crash-safe
Ransomware campaign use Unknown
Source publication date March 18, 2020
Platform OSX,Python,Unix
Source URL https://github.com/rapid7/metasploit-framework/tree/master/modules/exploits/osx/browser/safari_in_operator_side_effect.rb
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L Found at https://access.redhat.com/hydra/rest/securitydata/cve/CVE-2020-9850.json
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

network

adjacent_network

local

physical

low

high

none

low

high

none

required

unchanged

changed

high

low

none

high

low

none

high

low

none

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L Found at https://ftp.suse.com/pub/projects/security/yaml/suse-cvss-scores.yaml
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

network

adjacent_network

local

physical

low

high

none

low

high

none

required

unchanged

changed

high

low

none

high

low

none

high

low

none

Exploit Prediction Scoring System (EPSS)
Percentile 0.99236
EPSS Score 0.82826
Published At April 1, 2026, 12:55 p.m.
Date Actor Action Source VulnerableCode Version
2026-04-01T13:12:06.413779+00:00 Gentoo Importer Import https://security.gentoo.org/glsa/202007-11 38.0.0