DEBIAN-CVE-2021-41253

Source
https://security-tracker.debian.org/tracker/CVE-2021-41253
Import Source
https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2021-41253.json
JSON Data
https://api.osv.dev/v1/vulns/DEBIAN-CVE-2021-41253
Upstream
Published
2021-11-08T22:15:16.757Z
Modified
2025-11-19T02:04:27.358875Z
Severity
  • 8.1 (High) CVSS_V3 - CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H CVSS Calculator
Summary
[none]
Details

Zydis is an x86/x86-64 disassembler library. Users of Zydis versions v3.2.0 and older that use the string functions provided in zycore in order to append untrusted user data to the formatter buffer within their custom formatter hooks can run into heap buffer overflows. Older versions of Zydis failed to properly initialize the string object within the formatter buffer, forgetting to initialize a few fields, leaving their value to chance. This could then in turn cause zycore functions like ZyanStringAppend to make incorrect calculations for the new target size, resulting in heap memory corruption. This does not affect the regular uncustomized Zydis formatter, because Zydis internally doesn't use the string functions in zycore that act upon these fields. However, because the zycore string functions are the intended way to work with the formatter buffer for users of the library that wish to extend the formatter, we still consider this to be a vulnerability in Zydis. This bug is patched starting in version 3.2.1. As a workaround, users may refrain from using zycore string functions in their formatter hooks until updating to a patched version.

References

Affected packages

Debian:12 / zydis

Package

Name
zydis
Purl
pkg:deb/debian/zydis?arch=source

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected
Fixed
3.2.1-1

Ecosystem specific

{
    "urgency": "not yet assigned"
}

Database specific

source
"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2021-41253.json"

Debian:13 / zydis

Package

Name
zydis
Purl
pkg:deb/debian/zydis?arch=source

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected
Fixed
3.2.1-1

Ecosystem specific

{
    "urgency": "not yet assigned"
}

Database specific

source
"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2021-41253.json"

Debian:14 / zydis

Package

Name
zydis
Purl
pkg:deb/debian/zydis?arch=source

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected
Fixed
3.2.1-1

Ecosystem specific

{
    "urgency": "not yet assigned"
}

Database specific

source
"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2021-41253.json"