CVE-2024-25617 | Denial of Service in HTTP Header parser in squid proxy

Squid is an open source caching proxy for the Web supporting HTTP, HTTPS, FTP, and more. Due to a Collapse of Data into Unsafe Value bug ,Squid may be vulnerable to a Denial of Service attack against HTTP header parsing. This problem allows a remote client or a remote server to perform Denial of Service when sending oversized headers in HTTP messages. In versions of Squid prior to 6.5 this can be achieved if the request_header_max_size or reply_header_max_size settings are unchanged from the default. In Squid version 6.5 and later, the default setting of these parameters is safe. Squid will emit a critical warning in cache.log if the administrator is setting these parameters to unsafe values. Squid will not at this time prevent these settings from being changed to unsafe values. Users are advised to upgrade to version 6.5. There are no known workarounds for this vulnerability. This issue is also tracked as SQUID-2024:2

Published: 2024-02-14 Last update: 2026-06-17 Assigner: [email protected] Source: [email protected]
NVD Status：Analyzed，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2024-25617 is rated Moderate Risk (56.9/100): CVSS Medium severity, with high exploitation likelihood (EPSS 88.86%, 100th percentile). EPSS ranks this CVE among the most likely to be exploited in the near term. High exploitation likelihood—assess exposure and prioritize remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2024-25617

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-16 88.09% 88.86% +0.77%
2 2026-06-15 1.29% 88.09% +86.80%
3 2026-05-10 — 1.29% —

Full EPSS history (30 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2024-25617

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
5.3 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:L)
Might cause slowdowns, glitches, or partial disruption—not a full brick.
 3.9 1.4 [email protected]
7.5 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.9 3.6 [email protected]

Weakness enumeration for CVE-2024-25617

OS Trackers for CVE-2024-25617

vendor priority summary link
alpine — CVE-2024-25617: 1 source package rows (squid); 60 state rows across 5 repos (3.19-main, 3.20-main, 3.21-main, 3.22-main, edge-main); fixed 0, open 60. https://security.alpinelinux.org/vuln/CVE-2024-25617
debian not yet assigned CVE-2024-25617 not yet assigned priority: Debian including 1 source packages (squid), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2024-25617
redhat high — https://access.redhat.com/security/cve/CVE-2024-25617
suse high — https://www.suse.com/security/cve/CVE-2024-25617/
ubuntu medium CVE-2024-25617 medium priority: Ubuntu including 2 source packages (squid, squid3), 16 status rows across 8 suites (bionic, focal, jammy, mantic, noble, trusty, upstream, xenial): released 7, DNE 6, ignored 2, needs-triage 1. https://ubuntu.com/security/CVE-2024-25617

Affected software / configurations for CVE-2024-25617

Vendor Product Version Raw CPE
squid-cache squid >= 3.0, < 6.5 cpe:2.3:a:squid-cache:squid:*:*:*:*:*:*:*:*
netapp bluexp — cpe:2.3:a:netapp:bluexp:-:*:*:*:*:*:*:*

References for CVE-2024-25617

cvelogic Threat Intelligence