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CVE-2026-82309— Robots::Validate versions from 0.3.2 before 0.3.11 for Perl allow unbounded outbound DNS queries per validation via a forward-confirmation loop that does not bound the names it queries

Quick assessment

Affected
CVE-2026-82309
Exploitation
No confirmed in-the-wild exploitation; assess based on exposure
Recommended action
Check the vendor advisory and references for a fixed version. If immediate upgrade is impossible, restrict exposure and increase monitoring.

译文： 在 Perl 语言下，Robots::Validate 库从 0.3.2 到 0.3.11 之前的版本存在漏洞：由于在验证过程中存在一个“正向确认循环”，且该循环对所查询的域名数量没有上限，因此允许发起无限制的出站 DNS 查询。 具体机制如下： 函数首先针对客户端地址发起一次 PTR（反向）查询，然后保留那些与规则中定义的域名匹配的反向解析结果，并对每个保留的名称逐一发起正向（forward）查询，直到其中一个名称能反向解析回原客户端地址。这个名称列表没有任何数量限制，而由于客户端可以控制其自身地址的反向

AI Predicted 5.3 Difficulty: Moderate

Possible ATT&CK Techniques 1 AI

T1204 · User Execution

Affected Version Matrix 1

VendorProduct Version RangeStatus
None None 0.3.2< 0.3.11 affected

I. Basic Information for CVE-2026-82309

Vulnerability Information
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Vulnerability Title
Robots::Validate versions from 0.3.2 before 0.3.11 for Perl allow unbounded outbound DNS queries per validation via a forward-confirmation loop that does not bound the names it queries
Source: CVE Program / CVE List V5
Vulnerability Description
Robots::Validate versions from 0.3.2 before 0.3.11 for Perl allow unbounded outbound DNS queries per validation via a forward-confirmation loop that does not bound the names it queries. _check_dns issues one PTR query for the client address, keeps the returned names matching the rule's domain, and issues a forward query for each until one resolves back to that address. Nothing bounds that list, and a client controls the reverse zone for its own address, so it chooses how many names the PTR answer holds. Net::DNS refetches a truncated answer over TCP by default, so the 512-byte UDP payload does not cap it either. Any client whose User-Agent matches a rule with a domain reaches _check_dns. Each forward name is distinct and client-chosen, so every query misses the local cache and is resolved against the authoritative servers for that domain. The queries are synchronous, so the caller is held until all of them answer or time out.
Source: CVE Program / CVE List V5
CVSS Information
N/A
Source: CVE Program / CVE List V5
Vulnerability Type
不加限制或调节的资源分配
Source: CVE Program / CVE List V5

Affected Products

Vendor Product Affected Versions CPE Subscribe
- - 0.3.2 ~ 0.3.11 -

II. Public POCs for CVE-2026-82309

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III. Intelligence Information for CVE-2026-82309

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Patches & Fixes for CVE-2026-82309 (1)

Vendor Advisories for CVE-2026-82309 (1)

Other References for CVE-2026-82309 (1)

IV. Related Vulnerabilities

Same weakness: CWE-770

V. Comments for CVE-2026-82309

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