{"description":"Trending threats, MITRE ATT\u0026CK coverage, and detection metadata. Fed continuously.","feed_url":"https://feed.craftedsignal.io/tags/cache_poisoning/feed.json","home_page_url":"https://feed.craftedsignal.io/","items":[{"_cs_actors":[],"_cs_cpes":[],"_cs_cves":[],"_cs_exploited":false,"_cs_has_poc":false,"_cs_poc_references":[],"_cs_products":["libc"],"_cs_severities":["medium"],"_cs_tags":["dns","spoofing","glibc","cache_poisoning"],"_cs_type":"advisory","_cs_vendors":["GNU"],"content_html":"\u003cp\u003eMultiple vulnerabilities exist within the GNU libc library that could be exploited by a remote, anonymous attacker. These vulnerabilities allow for the manipulation of DNS responses. While specific CVEs are not mentioned in the source, the potential impact of successful exploitation includes redirecting users to malicious websites or services by poisoning the DNS resolver cache. This can lead to credential theft, malware infections, or other malicious activities. This issue impacts any system relying on the vulnerable GNU libc library for DNS resolution. Defenders should investigate which specific vulnerabilities are referenced in the advisory and apply appropriate mitigations.\u003c/p\u003e\n\u003ch2 id=\"attack-chain\"\u003eAttack Chain\u003c/h2\u003e\n\u003col\u003e\n\u003cli\u003eAttacker identifies a vulnerable system utilizing GNU libc for DNS resolution.\u003c/li\u003e\n\u003cli\u003eAttacker crafts malicious DNS responses to target the vulnerable resolver.\u003c/li\u003e\n\u003cli\u003eAttacker spoofs the source IP address of a legitimate DNS server.\u003c/li\u003e\n\u003cli\u003eThe vulnerable GNU libc resolver receives the spoofed DNS response.\u003c/li\u003e\n\u003cli\u003eDue to the vulnerability, the malicious DNS response is improperly validated.\u003c/li\u003e\n\u003cli\u003eThe malicious DNS response is cached by the resolver, poisoning its cache.\u003c/li\u003e\n\u003cli\u003eA user on the network queries the resolver for a legitimate domain (e.g., bank.com).\u003c/li\u003e\n\u003cli\u003eThe resolver returns the attacker-controlled IP address from the poisoned cache, redirecting the user to a malicious server.\u003c/li\u003e\n\u003c/ol\u003e\n\u003ch2 id=\"impact\"\u003eImpact\u003c/h2\u003e\n\u003cp\u003eSuccessful exploitation of these GNU libc vulnerabilities could lead to DNS cache poisoning, redirecting users to attacker-controlled servers. The number of victims and sectors targeted are unknown, but any system using the vulnerable GNU libc library is potentially at risk. The impact includes potential credential theft, malware infections, and other malicious activities due to users being redirected to fraudulent websites.\u003c/p\u003e\n\u003ch2 id=\"recommendation\"\u003eRecommendation\u003c/h2\u003e\n\u003cul\u003e\n\u003cli\u003eInvestigate the specific vulnerabilities referenced in the original BSI advisory (WID-SEC-2026-0817) to understand the technical details.\u003c/li\u003e\n\u003cli\u003eMonitor network traffic for suspicious DNS responses originating from unexpected sources using the rule \u0026ldquo;Detect Suspicious DNS Response IP\u0026rdquo; below.\u003c/li\u003e\n\u003cli\u003eImplement rate limiting on DNS responses to mitigate the effectiveness of cache poisoning attacks.\u003c/li\u003e\n\u003cli\u003eApply any available patches or updates to GNU libc as soon as they are released by the vendor.\u003c/li\u003e\n\u003cli\u003eEnable DNSSEC validation where possible to ensure the integrity of DNS responses.\u003c/li\u003e\n\u003c/ul\u003e\n","date_modified":"2026-05-15T08:44:28Z","date_published":"2026-05-15T08:44:28Z","id":"https://feed.craftedsignal.io/briefs/2026-05-glibc-dns-spoof/","summary":"A remote, anonymous attacker can exploit multiple vulnerabilities in GNU libc to manipulate DNS responses, potentially leading to redirection to malicious sites.","title":"GNU libc Vulnerabilities Allow DNS Response Manipulation","url":"https://feed.craftedsignal.io/briefs/2026-05-glibc-dns-spoof/"}],"language":"en","title":"CraftedSignal Threat Feed — Cache_poisoning","version":"https://jsonfeed.org/version/1.1"}