CVE-2021-33790

CRITICAL

9.8

CVSS Score

Published: May 31, 2021 at 04:00 AM UTC

Updated: June 17, 2026 at 03:55 AM UTC

1 product affected across 1 vendorReborncore· also runs on 1 platform

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Severity

CRITICAL9.8

Exploit prediction

EPSS 3%

Description

The RebornCore library before 4.7.3 allows remote code execution because it deserializes untrusted data in ObjectInputStream.readObject as part of reborncore.common.network.ExtendedPacketBuffer. An attacker can instantiate any class on the classpath with any data. A class usable for exploitation might or might not be present, depending on what Minecraft modifications are installed.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

Reborncore · Techreborn

95%

v ≤ 3.13.83.19.0 ≤ v < 3.19.54.2.0 ≤ v < 4.2.104.7.0 ≤ v < 4.7.3

Affected range stops below 3.19.5, so it looks safe — our inference, not a vendor statement

Affected range stops below 4.2.10, so it looks safe — our inference, not a vendor statement

Affected range stops below 4.7.3, so it looks safe — our inference, not a vendor statement

minecraft-minecraft (environment)

Runs on — not affected

The affected product only carries this flaw when running on these platforms. The platforms themselves are not vulnerable.

Minecraft · Minecraft

95%

Remediation

No guide yet

No remediation guidance has been written for this CVE yet, and no fixed version or vendor advisory is recorded against it.

References (3)

x_refsource_MISCThird Party Advisory

Source: [email protected]

https://github.com/TechReborn/RebornCore/security/advisories/GHSA-r7pg-4xrf-7mrm

x_refsource_MISCThird Party Advisory

Source: [email protected]

https://vuln.ryotak.me/advisories/45

x_refsource_MISCProductThird Party Advisory

Source: [email protected]

https://www.curseforge.com/minecraft/mc-mods/reborncore

CVSS

9.8CRITICAL[email protected]

Attack Vector: NETWORK
Complexity: LOW
Privileges: NONE
User Interaction: NONE
Scope: UNCHANGED
Confidentiality: HIGH
Integrity: HIGH
Availability: HIGH

Vector?

Quick Info

StatusMODIFIED

CWE

CWE-502

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