VulnerabilityPublished 13 Aug 2026Updated 8 Nov 2026

CVE-2024-37891: Icloudpd · urllib3's Proxy-Authorization request header isn't stripped during cross-origin redirects

Affects icloudpdSource GCVE Database

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Authoritative record:CVE-2024-37891· Medium 4.4

Not known to be exploited · CVSS 4.4 Medium : upgrade to 1.25.1 when convenient.

Data as of 9 Nov 2026, 06:35 UTC

CVSS 3.1 base score

4.4Medium

How severe the flaw is on the 0–10 CVSS scale.

Thin evidence

One scorer or none

CVSS scores by source
CNA (GitHub_M)	CVSS 3.1	4.4

Patch: Available – fixed in 1.25.1

CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:H/I:N/A:N

Attack Vector: Network
Attack Complexity: High
Privileges Required: High
User Interaction: None
Scope: Unchanged
Confidentiality: High
Integrity: None
Availability: None

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: High: A successful attack depends on conditions beyond the attacker's control. That is, a successful attack cannot be accomplished at will, but requires the attacker to invest in some measurable amount of effort in preparation or execution against the vulnerable component before a successful attack can be expected. For example, a successful attack may require an attacker to: gather knowledge about the environment in which the vulnerable target/component exists; prepare the target environment to improve exploit reliability; or inject themselves into the logical network path between the target and the resource requested by the victim in order to read and/or modify network communications (e.g., a man in the middle attack).
Privileges Required: High: The attacker is authorized with (i.e., requires) privileges that provide significant (e.g., administrative) control over the vulnerable component that could affect component-wide settings and files.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: High: There is total loss of confidentiality, resulting in all resources within the impacted component being divulged to the attacker. Alternatively, access to only some restricted information is obtained, but the disclosed information presents a direct, serious impact.
Integrity: None: There is no loss of integrity within the impacted component.
Availability: None: There is no impact to availability within the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 17 Jun 2024
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 8 Nov 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade icloudpd to 1.25.1.

Affected software

Product	Affected	Fixed in
Homebrewicloudpd`pkg:brew/icloudpd`Other threats	Affected >=1.17.3 <1.25.1	Fixed in 1.25.1

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

Users should upgrade to icloudpd version 1.25.1 or later, where the issue is fixed. Alternatively, users can avoid setting the Proxy-Authorization header manually without using urllib3's ProxyManager, or disable automatic HTTP redirects by setting redirects=False. Using urllib3's built-in proxy support is the recommended approach to safely handle the Proxy-Authorization header.

Description

CVE-2024-37891 is a vulnerability in urllib3's handling of the Proxy-Authorization HTTP header during cross-origin redirects. When the Proxy-Authorization header is set manually without using urllib3's proxy support, it is not stripped on redirects, potentially exposing sensitive authentication information. This scenario requires specific conditions, including manual header setting without proxy support, enabled HTTP redirects, and redirects to a malicious origin. The vulnerability affects icloudpd versions from 1.17.3 up to but not including 1.25.1. A fix is available in version 1.25.1.

Impact

The impact is limited to confidentiality, as the Proxy-Authorization header could be leaked to unintended origins during redirects. The vulnerability requires a high privilege level to set the header manually and conditions such as enabled HTTP redirects and redirects to malicious origins. There is no impact on integrity or availability. The CVSS score is 4.4 (medium severity), reflecting the low likelihood and limited impact.

Summary

The vulnerability arises because urllib3 does not strip the Proxy-Authorization header during cross-origin HTTP redirects if the header is set manually without using urllib3's ProxyManager. Normally, the header is only sent to configured proxies and stripped on redirects to prevent credential leakage. However, in this uncommon usage pattern, the header remains, risking exposure if redirected to a malicious origin. The issue affects icloudpd versions >=1.17.3 and <1.25.1. The fix in 1.25.1 ensures the Proxy-Authorization header is stripped by default during cross-origin redirects, mitigating the risk.

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Description

AI analysisMachine-generated, updated 9 Nov 2026, 06:35 UTC

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