Security Affairs newsletter Round 506 by Pierluigi Paganini

Nuclei is a vulnerability scanner powered by YAML based templates. Starting in version 3.0.0 and prior to version 3.3.2, a vulnerability in Nuclei's template signature verification system could allow an attacker to bypass the signature check and possibly execute malicious code via custom code template. The vulnerability is present in the template signature verification process, specifically in the `signer` package. The vulnerability stems from a discrepancy between how the signature verification process and the YAML parser handle newline characters, combined with the way multiple signatures are processed. This allows an attacker to inject malicious content into a template while maintaining a valid signature for the benign part of the template. CLI users are affected if they execute custom code templates from unverified sources. This includes templates authored by third parties or obtained from unverified repositories. SDK Users are affected if they are developers integrating Nuclei into their platforms, particularly if they permit the execution of custom code templates by end-users. The vulnerability is addressed in Nuclei v3.3.2. Users are strongly recommended to update to this version to mitigate the security risk. As an interim measure, users should refrain from using custom templates if unable to upgrade immediately. Only trusted, verified templates should be executed. Those who are unable to upgrade Nuclei should disable running custom code templates as a workaround.

CVE-2025-0282 is a stack-based buffer overflow (CWE-121) in Ivanti Connect Secure, Policy Secure, and ZTA Gateways, reachable by unauthenticated network input. An attacker can trigger it remotely by sending crafted, unauthenticated traffic to a vulnerable gateway, overwriting stack memory and gaining code execution under the appliance's context. Successful exploitation yields unauthenticated remote code execution on the device, giving the attacker control of the VPN/secure-access gateway and a foothold into the protected network. Organizations running any of the affected Ivanti secure-access products are exposed; the source data specifies no version ranges, so defenders should consult Ivanti's advisory for exact affected and fixed releases. The flaw is being actively exploited: it was added to CISA KEV on 2025-01-08 with known ransomware use, and EPSS assigns a 100% probability of exploitation within 30 days (100th percentile), despite no public PoC being known.

Do: Apply the patched releases identified in Ivanti's advisory and follow CISA's required action: hunt for signs of compromise, remediate if indicators are found, and apply updates before returning any device to service. Because exploitation is active and ransomware use is known, treat any appliance that was internet-reachable before patching as potentially compromised (check integrity, rotate credentials). Exact fixed versions were not included in the source data, so verify the correct update path for your branch (including older Connect Secure/Policy Secure releases) against Ivanti's bulletin.