CVE-2022-30780: Lighttpd 1.4.56 through 1.4.58 allows a remote attacker to cause a denial of service (CPU consumption from stuck connections) because…

PriorityP351high7.5CVSS 3.1

AVNACLPRNUINSUCNINAH

EPSS

56.42%

98.9th percentile

Lighttpd 1.4.56 through 1.4.58 allows a remote attacker to cause a denial of service (CPU consumption from stuck connections) because connection_read_header_more in connections.c has a typo that disrupts use of multiple read operations on large headers.

Affected

8 ranges

Vendor	Product	Version range	Fixed in
debian	lighttpd	< lighttpd 1.4.59-1 (bookworm)	lighttpd 1.4.59-1 (bookworm)
lighttpd	lighttpd	—	—
lighttpd	lighttpd	—	—
lighttpd	lighttpd	—	—
lighttpd	lighttpd	>= 0 < 1.4.59-1	1.4.59-1
lighttpd	lighttpd	>= 0 < 1.4.59-1	1.4.59-1
lighttpd	lighttpd	>= 0 < 1.4.59-1	1.4.59-1
lighttpd	lighttpd	>= 0 < 1.4.59-1	1.4.59-1

Detection & IOCsextracted from sources · hover to see the quote

→The vulnerability is a token-inconsistency bug (typo) in the function `connection_read_header_more` within `connections.c` in Lighttpd. Detection should focus on monitoring for stuck/long-lived connections consuming high CPU on Lighttpd 1.4.56–1.4.58, as the typo disrupts multiple read operations on large HTTP headers. ↗
→The affected Lighttpd versions are 1.4.56 through 1.4.58. Fingerprint server banners or package versions to identify unpatched instances; fixed in version 1.4.59. ↗
→CVE-2022-30780 is classified as a Token-Inconsistency Bug (TIB) — a misused code token at the semantic level. Detection tooling should look for anomalous CPU consumption patterns tied to persistent/stuck HTTP connections on affected Lighttpd versions. ↗

·The DoS is triggered by sending large HTTP headers to Lighttpd 1.4.56–1.4.58; the bug causes connections to become stuck and consume CPU rather than crashing the process, so crash-based detection (e.g., fuzzers monitoring for crashes) will not catch exploitation. ↗
·Debian packages for bookworm, bullseye, forky, sid, and trixie are all resolved at version 1.4.59-1; ensure patched package is deployed to remediate. ↗

CVSS provenance

nvdv3.17.5HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

nvdv2.05.0MEDIUMAV:N/AC:L/Au:N/C:N/I:N/A:P

osv7.5HIGH

vendor_debian7.5HIGH

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