Goal Reached Thanks to every supporter — we hit 100%!

Goal: 1000 CNY · Raised: 1359 CNY

100%
Buy Us a Coffee

CVE-2021-48019— Vyper before 0.2.9 Incorrect RETURNDATASIZE in create_forwarder_to Proxies

Quick assessment

Affected
vyperlang vyper
Exploitation
No confirmed in-the-wild exploitation; assess based on exposure
Recommended action
Check the vendor advisory and references for a fixed version. If immediate upgrade is impossible, restrict exposure and increase monitoring.

在 Vyper 0.2.9 之前的版本中，通过内置的 函数部署的前向代理合约会报告一个固定的 4096 字节 ，而非实际的返回数据大小。当被调用函数返回超过 4096 字节的数据且未进行返回数据清洗时，通过此类代理进行的调用可能导致数据损坏；同时，这类调用也会因无法通过严格的返回尺寸检查（例如 ）而失败。

CVSS 4.8 · Medium

Possible ATT&CK Techniques 1 AI

T1190 · Exploit Public-Facing Application
Get alerts for future matching vulnerabilities Log in to subscribe

I. Basic Information for CVE-2021-48019

Vulnerability Information
Have questions about the vulnerability? See if Shenlong's analysis helps!
View Shenlong Deep Dive ↗

Although we use advanced large model technology, its output may still contain inaccurate or outdated information.Shenlong tries to ensure data accuracy, but please verify and judge based on the actual situation.

Vulnerability Title
Vyper before 0.2.9 Incorrect RETURNDATASIZE in create_forwarder_to Proxies
Source: CVE Program / CVE List V5
Vulnerability Description
Vyper before 0.2.9 deploys forwarder proxies through the built-in create_forwarder_to function that report a fixed 4096-byte RETURNDATASIZE rather than the actual return data size. Calls through these proxies can yield corrupted data when a function returns more than 4096 bytes without return data sanitation, and fail strict return-size checks such as SafeERC20.safeTransfer.
Source: CVE Program / CVE List V5
CVSS Information
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:L
Source: CVE Program / CVE List V5
Vulnerability Type
使用不正确的长度值访问缓冲区
Source: CVE Program / CVE List V5

Affected Products

Vendor Product Affected Versions CPE Subscribe
vyperlang vyper 0 ~ 0.2.9 -

II. Public POCs for CVE-2021-48019

# POC Description Source Link Shenlong Link
AI-Generated POC Premium

No public POC found.

Login to generate AI POC

III. Intelligence Information for CVE-2021-48019

请登录查看更多情报信息。

Other References for CVE-2021-48019 (2)

Same Patch Batch · vyperlang · 2026-10-21 · 12 CVEs total

CVE-2021-48018 7.4 HIGH Vyper 0.2.13 before 0.2.15 Storage Corruption via @nonreentrant Decorator
CVE-2021-48020 6.5 MEDIUM Vyper before 0.3.0 Memory Corruption via Internal Function Calls in Arrays
CVE-2020-37286 6.5 MEDIUM Vyper 0.1.0b4 before 0.3.0 Memory Corruption via Nested Internal Function Calls
CVE-2026-114117 5.9 MEDIUM Vyper 0.3.8 through 0.5.0b1 Optimizer Miscompilation of msg.value | K in Ternary Branches
CVE-2020-37287 5.9 MEDIUM Vyper before 0.2.6 Call Stack Corruption via Complex Type Function Arguments
CVE-2026-114116 5.3 MEDIUM Vyper through 0.5.0b1 Literal Value Manipulation via Line Separators
CVE-2026-114114 5.3 MEDIUM Vyper through 0.5.0b1 Literal Value Substitution via Multi-byte Characters
CVE-2026-114118 4.8 MEDIUM Vyper 0.3.4 through 0.5.0b1 create_from_blueprint Offset Validation Bypass via Unsigned Wr
CVE-2026-114115 3.7 LOW Vyper 0.3.8 through 0.5.0b1 Memory Misread via Ternary Nested Array Selection
CVE-2020-37288 3.7 LOW Vyper 0.1.0b10 before 0.2.3 Invalid Jump Destination via Return in Nested Loops
CVE-2020-37289 3.7 LOW Vyper before 0.3.1 Improper Input Validation of uint8 Interface Return Values

IV. Related Vulnerabilities

Same product: vyper
Same vendor: vyperlang
Same weakness: CWE-805

V. Comments for CVE-2021-48019

No comments yet

Leave a comment