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YARA · Signature Base (Florian Roth / Nextron)

SIGNATURE_BASE_EXPL_CVE_2021_31166_Accept_Encoding_May21_1

Detects malformed Accept-Encoding header field as used in code exploiting CVE-2021-31166

ExploitSignature Base (Florian Roth / Nextron)Detection Rule License 1.1Compiles with YARA-X
Author
Florian Roth (Nextron Systems)
Date
2021-05-21
Modified
2023-12-05
Score / Quality
70 / 85

What this rule detects

Detects malformed Accept-Encoding header field as used in code exploiting CVE-2021-31166

It defines 1 patterns (0 text, 0 hex, 1 regex).

Summary generated from the rule's metadata and condition.

Rule source

Download .yar
expl-cve-2021-31166-accept-encoding-may21-1.yarDetection Rule License 1.1
rule SIGNATURE_BASE_EXPL_CVE_2021_31166_Accept_Encoding_May21_1 : CVE_2021_31166
{
	meta:
		description = "Detects malformed Accept-Encoding header field as used in code exploiting CVE-2021-31166"
		author = "Florian Roth (Nextron Systems)"
		id = "d0a79cdc-f3ee-58f9-805c-ec9eb7993315"
		date = "2021-05-21"
		modified = "2023-12-05"
		reference = "https://github.com/0vercl0k/CVE-2021-31166"
		source_url = "https://github.com/Neo23x0/signature-base/blob/94a1c48d7ab499879287ff611dfe7f9c56376030/yara/exploit_cve_2021_31166.yar#L2-L14"
		license_url = "https://github.com/Neo23x0/signature-base/blob/94a1c48d7ab499879287ff611dfe7f9c56376030/LICENSE"
		logic_hash = "5bb5b4093a7abe9d4297a4c047803b92f7c08f56f15b0f7bd163203ae47e026d"
		score = 70
		quality = 85
		tags = "CVE-2021-31166"

	strings:
		$xr1 = /[Aa]ccept\-[Ee]ncoding: [a-z\-]{1,16},([a-z\-\s]{1,16},|)*[\s]{1,20},/

	condition:
		1 of them
}

Strings (1 patterns)

IdentifierTypeValueModifiers
$xr1regex/[Aa]ccept\-[Ee]ncoding: [a-z\-]{1,16},([a-z\-\s]{1,16},|)*[\s]{1,20},/

Condition

1 of them

In plain words (Heuristic)

  • At least 1 patterns in the rule must match.

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References

Licence & attribution

Author: Florian Roth (Nextron Systems)

Source repository: Signature Base (Florian Roth / Nextron) @ 94a1c48d7a

Licence: Detection Rule License 1.1 (repository licence)

Original rule

Mirrored via YARA Forge 20260927, which prefixes rule names with the source and adds normalised meta fields.

Rule id: d0a79cdc-f3ee-58f9-805c-ec9eb7993315

Tags:CVE_2021_31166

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