CVE-2021-38614Public exploitNetwork attack vector

Proxy crash via malformed Range header

Published Aug 12, 2021 · Updated Aug 4, 2024

Heap-based buffer overflow in Polipo 1.1.1 and earlier allows remote attackers to crash the proxy via a malformed Range header. When NDEBUG removes the server.c range-bound assertion, descending byte bounds continue into processing that writes 10 bytes beyond a 7-byte heap allocation. The proxy port must accept the unauthenticated request; the demonstrated consequence is process termination and service interruption.

CVSS severity7.5
High
EPSS probability1.19%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Heap-based buffer overflow in Polipo 1.1.1 and earlier allows remote attackers to crash the proxy via a malformed Range header. When NDEBUG removes the server.c range-bound assertion, descending byte bounds continue into processing that writes 10 bytes beyond a 7-byte heap allocation. The proxy port must accept the unauthenticated request; the demonstrated consequence is process termination and service interruption.

The record

CVE
CVE-2021-38614
Published
Aug 12, 2021
Updated
Aug 4, 2024
Vendor
Polipo Project
Product
Polipo
Classifications
CWE-787, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 12, 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?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <=1.1.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Polipo Project · Polipoversion=0 <=1.1.1

Published CVSS scores

7.5NISTCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
5.0NISTAV:N/AC:L/Au:N/C:N/I:N/A:P
7.5CISA-ADPCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

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.

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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

CWE-787Out-of-bounds Write
T1499.004Application or System Exploitation

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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