CVE-2022-41556

Exp

A resource leak in gw_backend.c in lighttpd 1.4.56 through 1.4.66 could lead to a denial of service (connection-slot exhaustion) after a large amount of anomalous TCP behavior by clients. It is related to RDHUP mishandling in certain HTTP/1.1 chunked situations. Use of mod_fastcgi is, for example, affected. This is fixed in 1.4.67.

Published: 2022-10-06 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2022-41556 is rated High Exploit Risk (73.3/100): CVSS High severity, with medium exploitation likelihood (EPSS 1.81%). 1 public exploit reference(s) are indexed (Exploit-DB). Public exploits are available—assess exposure, apply mitigations, and prioritize patching.

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

Public exploit references (Exploit-DB) for CVE-2022-41556

EDB-ID Source Kind Published Link
— nvd_ref exploit_tag Exploit-DB ↗

Exploit prediction scoring system (EPSS) score for CVE-2022-41556

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 2026-05-16 2.52% 1.81% -0.71%
2 2026-05-15 1.81% 2.52% +0.71%
3 2026-04-01 — 1.81% —

Full EPSS history (26 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2022-41556

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
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-2022-41556

OS Trackers for CVE-2022-41556

vendor priority summary link
alpine high CVE-2022-41556: 1 source package rows (lighttpd); 12 state rows across 7 repos (3.17-main, 3.18-main, 3.19-main, 3.20-main, 3.21-main, 3.22-main, edge-main); fixed 7, open 5. https://security.alpinelinux.org/vuln/CVE-2022-41556
debian not yet assigned CVE-2022-41556 not yet assigned priority: Debian including 1 source packages (lighttpd), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2022-41556
gentoo low CVE-2022-41556: 1 GLSA(s) (202210-12), 1 atom(s) (www-servers/lighttpd); latest impact low. https://bugs.gentoo.org/buglist.cgi?quicksearch=CVE-2022-41556
suse medium CVE-2022-41556 severity moderate: SUSE including 40 source package names (lighttpd, lighttpd-1.4.67-2.1, …), 69 product×package rows across 9 product lines (SUSE Linux Enterprise High Availability Extension 12 SP4, SUSE Linux Enterprise High Availability Extension 12 SP5, … (9 product lines)): Fixed 65, Known Not Affected 4. https://www.suse.com/security/cve/CVE-2022-41556/
ubuntu medium CVE-2022-41556 medium priority: Ubuntu including 1 source packages (lighttpd), 13 status rows across 13 suites (bionic, focal, jammy, kinetic, lunar, mantic, noble, oracular, plucky, questing, trusty, upstream, xenial): not-affected 8, released 3, ignored 1, needs-triage 1. https://ubuntu.com/security/CVE-2022-41556

Affected software / configurations for CVE-2022-41556

Vendor Product Version Raw CPE
lighttpd lighttpd >= 1.4.56, < 1.4.67 cpe:2.3:a:lighttpd:lighttpd:*:*:*:*:*:*:*:*
fedoraproject fedora 35 cpe:2.3:o:fedoraproject:fedora:35:*:*:*:*:*:*:*

References for CVE-2022-41556

cvelogic Threat Intelligence