[From nobody Mon Jul 20 22:07:05 2026 Received: (at submit) by bugs.debian.org; 20 Jul 2026 19:48:28 +0000 X-Spam-Checker-Version: SpamAssassin 4.0.1-bugs.debian.org_2005_01_02 (2024-03-25) on buxtehude.debian.org X-Spam-Level: X-Spam-Status: No, score=-111.0 required=4.0 tests=ALL_TRUSTED,BAYES_00, DKIMWL_WL_HIGH,DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,FOURLA, FROMDEVELOPER,SPF_HELO_NONE,SPF_PASS,USER_IN_DKIM_WELCOMELIST, XMAILER_REPORTBUG autolearn=ham autolearn_force=no version=4.0.1-bugs.debian.org_2005_01_02 X-Spam-Bayes: score:0.0000 Tokens: new, 43; hammy, 150; neutral, 165; spammy, 0. spammytokens: hammytokens:0.000-+--Hx-spam-relays-external:sk:stravin, 0.000-+--H*RT:sk:stravin, 0.000-+--Hx-spam-relays-external:311, 0.000-+--H*RT:311, 0.000-+--H*RT:108 Return-path: <carnil@debian.org> Received: from stravinsky.debian.org ([2001:41b8:202:deb::311:108]:38662) by buxtehude.debian.org with esmtps (TLS1.3:ECDHE_SECP256R1__RSA_PSS_RSAE_SHA256__AES_256_GCM:256) (Exim 4.96) (envelope-from <carnil@debian.org>) id 1wltyV-005bkq-2Y for submit@bugs.debian.org; Mon, 20 Jul 2026 19:48:28 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=debian.org; s=smtpauto.stravinsky; h=X-Debian-User:Date:Message-ID:Subject:To:From: Content-Transfer-Encoding:MIME-Version:Content-Type:Reply-To:Cc:Content-ID: Content-Description:In-Reply-To:References; bh=IqyEFAbn8HQUwAe9JVW3z4+/klzfPf3FXr9O2yn9PUw=; b=rFMq8sgxWiUerhyIEcCKdrD2mt 7+wEDYoCcPBWz+1uuv5jdBafGJ7zKC8SmaIKC3mRPrqI3iZI/bJVa1qlqjI+sakFbms/EyIQywRd0 gdF2GNRBbaxdLAt8Pkw80+NmkeW257X2VMyfhFFg/VDok7xfBkEwR90HC6RXfb9J4w2FcAuL9pxZQ LBYSe3drAlsHkGCScU5VrW3T3SrF5/2iNy7vu3vNMIkV7iqBaBQTt+hAk9Ughl4kw2V6OrEUE+QvR UFjJ2X9Errhp3Agz7C8t7X9W7wZgo4X8hymYmWy8SgoB2VyIyW9JPUsz0Xy2aLsBdZxLyNAZGhJSI cxIUG8mQ==; Received: from authenticated-user by stravinsky.debian.org with esmtpsa (TLS1.3:ECDHE_X25519__RSA_PSS_RSAE_SHA256__AES_256_GCM:256) (Exim 4.96) (envelope-from <carnil@debian.org>) id 1wltyT-001fuH-1q for submit@bugs.debian.org; Mon, 20 Jul 2026 19:48:26 +0000 Received: from eldamar.lan (localhost [127.0.0.1]) by eldamar.lan (Postfix) with ESMTP id 3A2CCBE2EE7 for <submit@bugs.debian.org>; Mon, 20 Jul 2026 21:48:23 +0200 (CEST) Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit From: Salvatore Bonaccorso <carnil@debian.org> To: Debian Bug Tracking System <submit@bugs.debian.org> Subject: libnet-dns-perl: CVE-2026-64193 CVE-2026-64194 Message-ID: <178457690318.741501.5097559482442261734.reportbug@eldamar.lan> X-Mailer: reportbug 13.2.0+nmu1 Date: Mon, 20 Jul 2026 21:48:23 +0200 X-Debian-User: carnil Delivered-To: submit@bugs.debian.org Source: libnet-dns-perl Version: 1.55-1 Severity: important Tags: security upstream X-Debbugs-Cc: carnil@debian.org, Debian Security Team <team@security.debian.org> Hi, The following vulnerabilities were published for libnet-dns-perl. CVE-2026-64193[0]: | Net::DNS versions through 1.55 for Perl allow remote execution | injection via EDNS EXTENDED ERROR. | Net::DNS::RR::OPT::EXTENDED_ERROR::_decompose parses the EXTRA-TEXT | field of an EDNS EXTENDED-ERROR option (RFC 8914) by tokenising the | raw bytes and passing the result to Perl's eval. There is some | escaping done for $ and @, but not for backticks. This can be | exploited for command execution if $pkt->edns->option('EXTENDED- | ERROR') is called in array context, for example with a payload of | {0:`"<command>"`} in EXTRA-TEXT. CVE-2026-64194[1]: | Net::DNS versions through 1.55 for Perl allow Denial of Service via | deep DNS compression pointer chains. Net::DNS::DomainName::decode | follows RFC 1035 compression pointers by recursing into itself with | no depth limit. It is possible to construct a name which saturates | the call stack (at least with larger TCP responses), leading to a | potential Denial of Service. The guard `$link < $offset` prevents | forward and circular chains, but still allows arbitrarily long | backward chains. The per-offset cache (`$cache`) is populated at the | start of each call and short-circuits only re-traverses of the same | offset - the initial descent through a fresh chain still recurses at | full depth. A crafted packet can chain two-byte compression | pointers so that each one points two bytes earlier than the | previous, producing a chain length of `offset / 2`. For the 14-bit | pointer field (max offset 16383) this gives up to ~8191 recursive | frames. For a TCP DNS message the limit is the 16-bit length field | (~32767 frames). Perl's default C stack handles only a few thousand | frames; beyond that the process receives SIGSEGV or similar, which | is a denial-of-service for any application parsing untrusted DNS | data. The vulnerability is triggered by | `Net::DNS::Packet->new(\$wire)` i.e. any point where the library | decodes a DNS message from the network. If you fix the vulnerabilities please also make sure to include the CVE (Common Vulnerabilities & Exposures) ids in your changelog entry. For further information see: [0] https://security-tracker.debian.org/tracker/CVE-2026-64193 https://www.cve.org/CVERecord?id=CVE-2026-64193 [1] https://security-tracker.debian.org/tracker/CVE-2026-64194 https://www.cve.org/CVERecord?id=CVE-2026-64194 Please adjust the affected versions in the BTS as needed. Regards, Salvatore ]