Every CVE Search/ Get API key

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...

7.5 HighFix available

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

3.83%Up 2.9 points since Oct 7, 2022
90%50%10%1%

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 HighCVSS: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 HighCVSS: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 HighCVSS: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 HighCVSS: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 HighCVSS: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 HighCVSS: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

Affected packages
PackageAffectedFixed
lighttpd
Alpine:v3.15
1.4.56 up to 1.4.67-r0
1.4.67-r0
lighttpd
Alpine:v3.16
1.4.56 up to 1.4.67-r0
1.4.67-r0
lighttpd
Alpine:v3.17
1.4.56 up to 1.4.67-r0
1.4.67-r0
lighttpd
Alpine:v3.18
1.4.56 up to 1.4.67-r0
1.4.67-r0
lighttpd
Alpine:v3.19
1.4.56 up to 1.4.67-r0
1.4.67-r0
lighttpd
Alpine:v3.20
1.4.56 up to 1.4.67-r0
1.4.67-r0
lighttpd
Alpine:v3.21
1.4.56 up to 1.4.67-r0
1.4.67-r0
lighttpd
Alpine:v3.22
1.4.56 up to 1.4.67-r0
1.4.67-r0
lighttpd
Alpine:v3.23
1.4.56 up to 1.4.67-r0
1.4.67-r0
lighttpd
Alpine:v3.24
1.4.56 up to 1.4.67-r0
1.4.67-r0
Show 17 moreShow less
Affected packages
PackageAffectedFixed
lighttpd
Debian:12
before 1.4.67-1
1.4.67-1
lighttpd
Debian:13
before 1.4.67-1
1.4.67-1
lighttpd
Debian:14
before 1.4.67-1
1.4.67-1
lighttpd
Debian: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
lighttpd
Mageia:8
From an advisory covering 2 CVEs
before 1.4.59-1.2.mga8
1.4.59-1.2.mga8
lighttpd
openEuler:20.03-LTS-SP1
From an advisory covering 2 CVEs
before 1.4.67-1.oe1
1.4.67-1.oe1
lighttpd
openEuler:20.03-LTS-SP3
From an advisory covering 2 CVEs
before 1.4.67-1.oe1
1.4.67-1.oe1
lighttpd
openEuler:22.03-LTS
From an advisory covering 2 CVEs
before 1.4.67-1.oe2203
1.4.67-1.oe2203
lighttpd
Ubuntu: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
lighttpd
Ubuntu: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
lighttpd
Ubuntu: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
lighttpd
Ubuntu: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
lighttpd
SUSE:Package Hub 15 SP3
before 1.4.67-bp154.2.6.1
1.4.67-bp154.2.6.1
lighttpd
SUSE:Package Hub 15 SP4
before 1.4.67-bp154.2.6.1
1.4.67-bp154.2.6.1
lighttpd
openSUSE:Leap 15.3
before 1.4.67-bp154.2.6.1
1.4.67-bp154.2.6.1
lighttpd
openSUSE:Leap 15.4
before 1.4.67-bp154.2.6.1
1.4.67-bp154.2.6.1
lighttpd
openSUSE:Tumbleweed
before 1.4.67-2.1
1.4.67-2.1

History

History
RecordedChangedSources
affected, factsOSV
aliasesEUVD
first indexedCVE 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

Show 17 moreShow less
MoveEnter Open