{"description":"Trending threats, MITRE ATT\u0026CK coverage, and detection metadata. Fed continuously.","feed_url":"https://feed.craftedsignal.io/products/binutils-bfd-library-dlx-elf-backend/feed.json","home_page_url":"https://feed.craftedsignal.io/","items":[{"_cs_actors":[],"_cs_cpes":[],"_cs_cves":[{"cvss":7.8,"id":"CVE-2026-18220"}],"_cs_exploited":false,"_cs_has_poc":false,"_cs_poc_references":[],"_cs_products":["binutils (BFD library DLX ELF backend)"],"_cs_severities":["high"],"_cs_tags":["vulnerability","code-execution","binutils","linux"],"_cs_type":"advisory","_cs_vendors":["GNU"],"content_html":"\u003cp\u003eA critical out-of-bounds write vulnerability, identified as CVE-2026-18220, has been discovered in the BFD library's DLX ELF backend (specifically \u003ccode\u003ebfd/elf32-dlx.c\u003c/code\u003e) within GNU binutils. The \u003ccode\u003edlx_rtype_to_howto()\u003c/code\u003e function, responsible for mapping ELF relocation types to internal \u003ccode\u003ehowto\u003c/code\u003e structures, lacks adequate bounds checking. Attackers can manipulate relocation type values (via \u003ccode\u003eELF32_R_TYPE(r_info)\u003c/code\u003e) in a specially crafted ELF/DLX object file to index out-of-bounds into the \u003ccode\u003edlx_elf_howto_table[]\u003c/code\u003e array. This flaw can be exploited to achieve arbitrary code execution through a File Stream Oriented Programming (FSOP) attack targeting \u003ccode\u003eglibc FILE\u003c/code\u003e structures, ultimately redirecting control flow to \u003ccode\u003esystem()\u003c/code\u003e. The vulnerability poses a significant risk to environments like CI/CD pipelines, developer workstations, automated security scanners, or package build systems that process untrusted binaries, particularly when binutils is compiled with the DLX backend enabled (e.g., via \u003ccode\u003e--enable-targets=all\u003c/code\u003e).\u003c/p\u003e\n\u003ch2 id=\"attack-chain\"\u003eAttack Chain\u003c/h2\u003e\n\u003col\u003e\n\u003cli\u003eAn attacker crafts a malicious ELF/DLX object file containing carefully chosen relocation type values designed to trigger an out-of-bounds write.\u003c/li\u003e\n\u003cli\u003eThe victim's system processes the untrusted, malicious ELF/DLX object file using a BFD-consuming tool such as \u003ccode\u003eobjdump\u003c/code\u003e, \u003ccode\u003ereadelf\u003c/code\u003e, \u003ccode\u003estrip\u003c/code\u003e, \u003ccode\u003eld\u003c/code\u003e, \u003ccode\u003enm\u003c/code\u003e, or \u003ccode\u003eobjcopy\u003c/code\u003e.\u003c/li\u003e\n\u003cli\u003eDuring binary parsing, the vulnerable \u003ccode\u003edlx_rtype_to_howto()\u003c/code\u003e function within the BFD library attempts to map the attacker-controlled relocation type values.\u003c/li\u003e\n\u003cli\u003eDue to insufficient bounds checking, the attacker's specially crafted relocation type values lead to an out-of-bounds index into the \u003ccode\u003edlx_elf_howto_table[]\u003c/code\u003e array.\u003c/li\u003e\n\u003cli\u003eThis out-of-bounds write is leveraged by the attacker to corrupt \u003ccode\u003eglibc FILE\u003c/code\u003e structures, initiating a File Stream Oriented Programming (FSOP) attack.\u003c/li\u003e\n\u003cli\u003eThe FSOP attack redirects the program's control flow, specifically through \u003ccode\u003estderr\u003c/code\u003e, to execute the \u003ccode\u003esystem()\u003c/code\u003e function.\u003c/li\u003e\n\u003cli\u003eArbitrary code specified by the attacker is executed on the compromised system, granting the attacker control over the vulnerable process and potentially the host system.\u003c/li\u003e\n\u003c/ol\u003e\n\u003ch2 id=\"impact\"\u003eImpact\u003c/h2\u003e\n\u003cp\u003eSuccessful exploitation of CVE-2026-18220 results in arbitrary code execution on affected systems. This can lead to complete compromise of developer workstations, CI/CD pipeline servers, automated security analysis tools, or package build systems that process untrusted or maliciously crafted ELF/DLX binaries. The severity is reflected by its CVSS v3.1 Base Score of 7.8 (High). Such compromise can enable attackers to exfiltrate sensitive intellectual property, inject malicious code into software build processes, or gain a foothold into critical development infrastructure, potentially leading to supply chain attacks.\u003c/p\u003e\n\u003ch2 id=\"recommendation\"\u003eRecommendation\u003c/h2\u003e\n\u003cul\u003e\n\u003cli\u003ePatch CVE-2026-18220 immediately by updating GNU binutils to the latest secure version available from GNU or your operating system vendor.\u003c/li\u003e\n\u003cli\u003eRestrict the processing of untrusted ELF/DLX binaries by BFD-consuming tools on critical systems such as CI/CD pipelines and developer workstations.\u003c/li\u003e\n\u003cli\u003eWhere binutils functionality is required, ensure the build configuration (\u003ccode\u003e--enable-targets=all\u003c/code\u003e) does not inadvertently enable the DLX backend if it is not explicitly needed.\u003c/li\u003e\n\u003c/ul\u003e\n","date_modified":"2026-07-29T11:22:30Z","date_published":"2026-07-29T11:22:30Z","id":"https://feed.craftedsignal.io/briefs/2026-07-cve-2026-18220-gnu-binutils-oob-write/","summary":"An out-of-bounds write vulnerability, CVE-2026-18220, exists in the BFD library's DLX ELF backend (bfd/elf32-dlx.c) in GNU binutils, allowing attackers to achieve arbitrary code execution via a specially crafted ELF/DLX object file processed by BFD-consuming tools.","title":"CVE-2026-18220: Out-of-Bounds Write in GNU Binutils BFD Library Leading to Arbitrary Code Execution","url":"https://feed.craftedsignal.io/briefs/2026-07-cve-2026-18220-gnu-binutils-oob-write/"}],"language":"en","title":"CraftedSignal Threat Feed - Binutils (BFD Library DLX ELF Backend)","version":"https://jsonfeed.org/version/1.1"}