CVE-2020-17753Public exploitNetwork attack vector

Arbitrary token transfer via tx.origin authorization

Published Jun 24, 2021 · Updated Aug 4, 2024

Authorization bypass in the RC Ethereum token smart contract allows attackers to transfer arbitrary token amounts to arbitrary addresses. addMeByRC trusts tx.origin to identify the owner, so a malicious intermediary contract invoked by that owner becomes authorized as an RC contract. Exploitation requires the token-sale owner to invoke an attacker-controlled contract, after which its claim call transfers tokens.

CVSS severity6.5
Medium
EPSS probability1.51%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Authorization bypass in the RC Ethereum token smart contract allows attackers to transfer arbitrary token amounts to arbitrary addresses. addMeByRC trusts tx.origin to identify the owner, so a malicious intermediary contract invoked by that owner becomes authorized as an RC contract. Exploitation requires the token-sale owner to invoke an attacker-controlled contract, after which its claim call transfers tokens.

The record

CVE
CVE-2020-17753
Published
Jun 24, 2021
Updated
Aug 4, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
T1204.001
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 24, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

4.3NIST NVDAV:N/AC:M/Au:N/C:N/I:P/A:N
6.5NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

T1204.001User Execution: Malicious Link

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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