CVE-2022-41556
A resource leak in gw_backend.c in lighttpd 1.4.56 through 1.4.66 could lead to a denial of...
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.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- None
- Integrity
- None
- Availability
- High
Exploit likelihood
What each source reports
NVD Score used
7.5
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.
- Record
CVE-2022-41556- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-401
- Updated
- 2026-11-02
CVE List No score
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.
- Record
CVE-2022-41556- Updated
- 2026-11-02
EUVDEUVD-2022-44748 No score
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.
- Record
EUVD-2022-44748- Updated
- 2026-11-03
GitHub AdvisoriesGHSA-jm88-vr5q-23rj
7.5
A resource leak in gw_backend.c in lighttpd 1.4.56 through 1.4.66 could lead to a denial of...
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.
- Record
GHSA-jm88-vr5q-23rj- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-401
- Updated
- 2026-11-02
OSVALPINE-CVE-2022-41556
7.5
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.
- Record
ALPINE-CVE-2022-41556- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-03
OSVDEBIAN-CVE-2022-41556
7.5
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.
- Record
DEBIAN-CVE-2022-41556- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-03
Show 7 moreShow less
OSVOESA-2022-1989
7.5
lighttpd security update
Secure, fast, compliant and very flexible web-server which has been optimized for high-performance environments. It has a very low memory footprint compared to other webservers and takes care of cpu-load. Its advanced feature-set (FastCGI, CGI, Auth, Output-Compression, URL-Rewriting and many more) make it the perfect webserver-software for every server that is suffering load problems.
Security Fix(es):
In lighttpd 1.4.65, mod_wstunnel does not initialize a handler function pointer if an invalid HTTP request (websocket handshake) is received. It leads to null pointer dereference which crashes the server. It could be used by an external attacker to cause denial of service condition.(CVE-2022-37797)
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.(CVE-2022-41556)
- Record
OESA-2022-1989- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-02
OSVUBUNTU-CVE-2022-41556
7.5
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.
- Record
UBUNTU-CVE-2022-41556- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-02
OSV No score
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.
- Record
CVE-2022-41556- Updated
- 2026-11-02
OSVMGASA-2022-0369 No score
Updated lighttpd packages fix security vulnerability
In lighttpd 1.4.65, mod_wstunnel does not initialize a handler function pointer if an invalid HTTP request (websocket handshake) is received. It leads to null pointer dereference which crashes the server. It could be used by an external attacker to cause denial of service condition. (CVE-2022-37797)
A resource leak in mod_fastcgi and mod_scgi could lead to a denial of service after a large number of bad HTTP requests. (CVE-2022-41556)
- Record
MGASA-2022-0369- Updated
- 2026-11-02
OSVopenSUSE-SU-2022:10140-1 No score
Security update for lighttpd
This update for lighttpd fixes the following issues:
lighttpd was updated to 1.4.67:
- Update comment about TCP_INFO on OpenBSD
- [mod_ajp13] fix crash with bad response headers (fixes #3170)
- [core] handle RDHUP when collecting chunked body CVE-2022-41556 (boo#1203872)
- [core] tweak streaming request body to backends
- [core] handle ENOSPC with pwritev() (#3171)
- [core] manually calculate off_t max (fixes #3171)
- [autoconf] force large file support (#3171)
- [multiple] quiet coverity warnings using casts
- [meson] add license keyword to project declaration
- Record
openSUSE-SU-2022:10140-1- Updated
- 2026-11-02
OSVopenSUSE-SU-2024:12382-1 No score
lighttpd-1.4.67-2.1 on GA media
These are all security issues fixed in the lighttpd-1.4.67-2.1 package on the GA media of openSUSE Tumbleweed.
- Record
openSUSE-SU-2024:12382-1- Updated
- 2026-11-02
OSVUSN-5903-1 No score
lighttpd vulnerabilities
It was discovered that lighttpd incorrectly handled certain inputs, which could result in a stack buffer overflow. A remote attacker could possibly use this issue to cause a denial of service (DoS). (CVE-2022-22707, CVE-2022-41556)
- Record
USN-5903-1- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
lighttpdAlpine:v3.15 |
1.4.56 up to 1.4.67-r0 | 1.4.67-r0 |
lighttpdAlpine:v3.16 |
1.4.56 up to 1.4.67-r0 | 1.4.67-r0 |
lighttpdAlpine:v3.17 |
1.4.56 up to 1.4.67-r0 | 1.4.67-r0 |
lighttpdAlpine:v3.18 |
1.4.56 up to 1.4.67-r0 | 1.4.67-r0 |
lighttpdAlpine:v3.19 |
1.4.56 up to 1.4.67-r0 | 1.4.67-r0 |
lighttpdAlpine:v3.20 |
1.4.56 up to 1.4.67-r0 | 1.4.67-r0 |
lighttpdAlpine:v3.21 |
1.4.56 up to 1.4.67-r0 | 1.4.67-r0 |
lighttpdAlpine:v3.22 |
1.4.56 up to 1.4.67-r0 | 1.4.67-r0 |
lighttpdAlpine:v3.23 |
1.4.56 up to 1.4.67-r0 | 1.4.67-r0 |
lighttpdAlpine:v3.24 |
1.4.56 up to 1.4.67-r0 | 1.4.67-r0 |
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| Package | Affected | Fixed |
|---|---|---|
lighttpdDebian:12 |
before 1.4.67-1 | 1.4.67-1 |
lighttpdDebian:13 |
before 1.4.67-1 | 1.4.67-1 |
lighttpdDebian:14 |
before 1.4.67-1 | 1.4.67-1 |
lighttpdDebian:11 From an advisory covering 2 CVEs |
before 1.4.59-1+deb11u2, plus listed versions 1.4.59-11.4.59-1+deb11u1 |
1.4.59-1+deb11u2 |
lighttpdMageia:8 From an advisory covering 2 CVEs |
before 1.4.59-1.2.mga8 | 1.4.59-1.2.mga8 |
lighttpdopenEuler:20.03-LTS-SP1 From an advisory covering 2 CVEs |
before 1.4.67-1.oe1 | 1.4.67-1.oe1 |
lighttpdopenEuler:20.03-LTS-SP3 From an advisory covering 2 CVEs |
before 1.4.67-1.oe1 | 1.4.67-1.oe1 |
lighttpdopenEuler:22.03-LTS From an advisory covering 2 CVEs |
before 1.4.67-1.oe2203 | 1.4.67-1.oe2203 |
lighttpdUbuntu:Pro:14.04:LTS |
All versions, plus listed versions 1.4.31-3ubuntu31.4.33-1ubuntu11.4.33-1+nmu2ubuntu11.4.33-1+nmu2ubuntu21.4.33-1+nmu2ubuntu2.11.4.33-1+nmu2ubuntu2.1+esm1 |
None known |
lighttpdUbuntu:22.04:LTS |
before 1.4.63-1ubuntu3.1, plus listed versions 1.4.59-1ubuntu21.4.59-1ubuntu31.4.63-1ubuntu11.4.63-1ubuntu21.4.63-1ubuntu3 |
1.4.63-1ubuntu3.1 |
lighttpdUbuntu:20.04:LTS From an advisory covering 2 CVEs |
before 1.4.55-1ubuntu1.20.04.2, plus listed versions 1.4.53-4ubuntu21.4.54-2ubuntu11.4.55-1ubuntu11.4.55-1ubuntu1.20.04.1 |
1.4.55-1ubuntu1.20.04.2 |
lighttpdUbuntu:22.04:LTS From an advisory covering 2 CVEs |
before 1.4.63-1ubuntu3.1, plus listed versions 1.4.59-1ubuntu21.4.59-1ubuntu31.4.63-1ubuntu11.4.63-1ubuntu21.4.63-1ubuntu3 |
1.4.63-1ubuntu3.1 |
lighttpdSUSE:Package Hub 15 SP3 |
before 1.4.67-bp154.2.6.1 | 1.4.67-bp154.2.6.1 |
lighttpdSUSE:Package Hub 15 SP4 |
before 1.4.67-bp154.2.6.1 | 1.4.67-bp154.2.6.1 |
lighttpdopenSUSE:Leap 15.3 |
before 1.4.67-bp154.2.6.1 | 1.4.67-bp154.2.6.1 |
lighttpdopenSUSE:Leap 15.4 |
before 1.4.67-bp154.2.6.1 | 1.4.67-bp154.2.6.1 |
lighttpdopenSUSE:Tumbleweed |
before 1.4.67-2.1 | 1.4.67-2.1 |
History
| Recorded | Changed | Sources |
|---|---|---|
| affected, facts | OSV | |
| aliases | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2022-41556 is a high vulnerability (CVSS 7.5) in Lighttpd, published September 28, 2022. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 3.83%, the 90th percentile. Fixed in lighttpd 1.4.67-r0.
References
git.lighttpd.net/lighttpd/lighttpd1.4/commit/b18de6f9264f914f7bf493abd3b6059343548e50
github.com/lighttpd/lighttpd1.4/pull/115
github.com/lighttpd/lighttpd1.4/compare/lighttpd-1.4.66...lighttpd-1.4.67
lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/OVOSBSCMLGCHH2Z74H64ZWVDFJFQTBC2
security.gentoo.org/glsa/202210-12
nvd.nist.gov/vuln/detail/CVE-2022-41556
Show 17 moreShow less
lists.fedoraproject.org/archives/list/[email protected]/message/OVOSBSCMLGCHH2Z74H64ZWVDFJFQTBC2
github.com/advisories/GHSA-jm88-vr5q-23rj
security.alpinelinux.org/vuln/CVE-2022-41556
github.com/CVEProject/cvelistV5/tree/main/cves/2022/41xxx/CVE-2022-41556.json
security-tracker.debian.org/tracker/CVE-2022-41556
advisories.mageia.org/MGASA-2022-0369.html
bugs.mageia.org/show_bug.cgi?id=30912
debian.org/security/2022/dsa-5243
openeuler.org/en/security/safety-bulletin/detail.html?id=openEuler-SA-2022-1989
nvd.nist.gov/vuln/detail/CVE-2022-37797
ubuntu.com/security/CVE-2022-41556
ubuntu.com/security/notices/USN-5903-1
cve.org/CVERecord?id=CVE-2022-41556
ubuntu.com/security/CVE-2022-22707
lists.opensuse.org/archives/list/[email protected]/thread/T6C6UOQL3XPIYN6MAYXR6H6PCUA7Q4N4
bugzilla.suse.com/1203872
suse.com/security/cve/CVE-2022-41556