Detections
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EulerOS 2.0 SP12 : ruby (EulerOS-SA-2026-4453)
medium Nessus Plugin ID 376744
Synopsis
The remote EulerOS host is missing multiple security updates.Description
According to the versions of the ruby packages installed, the EulerOS installation on the remote host is affected by the following vulnerabilities :REJECTED Rejected reason: The RubyGems maintainers determined that the reported symlink-following behavior during gem extraction is not a security vulnerability, so no vulnerability exists for this record to describe.(CVE-2026-82455)
zlib is a Ruby interface for the zlib compression/decompression library. Versions 3.0.0 and below, 3.1.0, 3.1.1, 3.2.0 and 3.2.1 contain a buffer overflow vulnerability in the Zlib::GzipReader. The zstream_buffer_ungets function prepends caller-provided bytes ahead of previously produced output but fails to guarantee the backing Ruby string has enough capacity before the memmove shifts the existing data. This can lead to memory corruption when the buffer length exceeds capacity. This issue has been fixed in versions 3.0.1, 3.1.2 and 3.2.3.(CVE-2026-27820)
The attack vector is a potential Denial of Service (DoS). The vulnerability is caused by an insufficient check on the length of a decompressed domain name within a DNS packet._x000D_
_x000D_ An attacker can craft a malicious DNS packet containing a highly compressed domain name. When the resolv library parses such a packet, the name decompression process consumes a large amount of CPU resources, as the library does not limit the resulting length of the name._x000D_
_x000D_ This resource consumption can cause the application thread to become unresponsive, resulting in a Denial of Service condition.(CVE-2025-24294)
An issue was discovered in the resolv gem before 0.7.2 for Ruby. Resolv::DNS::MessageEncoder wrote a DNS label's length into a single octet without checking its range. A label longer than 255 octets had its length stored modulo 256 but the label data was written unchanged, and thus the bytes on the wire described a different name than the one the application asked to encode. RFC 1035 section 2.3.4 limits a label to 63 octets, and the two high bits of the length octet are reserved for compression pointers.
put_string packed the length with put_pack('C', d.length) and put_label used it for labels, and thus any value from 0 to 255 could end up as a label length octet, including the reserved 0x40-0xBF range and the 0xC0-0xFF pointer range. Resolv::DNS::Name.create did not check per-label or total name length either, and thus an attacker-controlled hostname reached the encoder unchanged. An application that resolves an attacker-controlled hostname sends a query whose wire bytes name a domain the attacker chose. A hostname suffix that the application validates against an allowlist becomes padding that never appears on the wire, and thus allowlist and egress checks can be bypassed. The recursive resolver caches the response under the attacker's name, and DNS logs record that name rather than the one the application asked for. A label length whose low octet lands in the 0xC0-0xFF range produces a length octet that conforming parsers read as the start of a compression pointer, with the following attacker-controlled byte as the offset.(CVE-2026-80213)
Net::IMAP implements Internet Message Access Protocol (IMAP) client functionality in Ruby. Prior to 0.6.5 and 0.5.15, several Net::IMAP commands accept a 'raw data' argument that is sent verbatim after validation to prevent command injection. However, if a server does not support non-synchronizing literals, it may still be possible to inject arbitrary IMAP commands inside non-synchronizing literals. A server without support for non-synchronizing literals may interpret the '+}\r\n' as the end of a malformed command line and respond with a tagged BAD. In that case, the contents of the literal will be interpreted as one or more new pipelined commands, allowing a CRLF command injection attack to succeed. This affects criteria for #search and #uid_search; search_keys for #sort, #thread, #uid_sort, and #uid_thread; and attr for #fetch and #uid_fetch. This vulnerability is fixed in 0.6.5 and 0.5.15.(CVE-2026-47240)
Net::IMAP implements Internet Message Access Protocol (IMAP) client functionality in Ruby. Prior to 0.6.5 and 0.5.15, several Net::IMAP commands accept a raw string argument which is only validated to prevent CRLF injection and then sent verbatim. If this string is derived from user-controlled input, an attacker can force the next command to be absorbed as a continuation of the first command. This will cause the first command to eventually fail, but also prevents it from returning until another command is sent (from another thread). That other command will not return until the connection is closed. This vulnerability is fixed in 0.6.5 and 0.5.15.(CVE-2026-47241)
An issue was discovered in the resolv gem before 0.7.2 for Ruby. Resolv::DNS::Resource.get_class, Resolv::DNS::Resource::Generic.create, and Resolv::DNS::SvcParam::Generic.create generate a new class for each unknown DNS resource record (type, class) pair, or each unknown SvcParamKey, encountered while decoding a response. Each generated class was permanently registered both as a constant on Resource (or SvcParam::Generic) and as an entry in a class-lookup hash (ClassHash), and thus the class remained reachable through that constant after the response was discarded. Type and class are each 16-bit values, and thus an attacker controlling DNS responses (a spoofed response, or a malicious or hijacked upstream DNS server) has roughly 2^32 distinct (type, class) pairs to choose from. A single response of a few hundred kilobytes carrying tens of thousands of distinct unknown types permanently grows process memory by tens of megabytes; repeated responses accumulate without bound and are never reclaimed by garbage collection, because the constant keeps each class alive. Any code path that calls Resolv::DNS::Message.decode on attacker-influenced DNS responses is affected. resolv is a default gem, and thus this is reachable from a plain Ruby installation without any additional dependency.(CVE-2026-80212)
Tenable has extracted the preceding description block directly from the EulerOS ruby security advisory.
Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.
Solution
Update the affected ruby packages.See Also
Plugin Details
Severity: Medium
ID: 376744
File Name: EulerOS_SA-2026-4453.nasl
Version: 1.1
Type: Local
Family: Huawei Local Security Checks
Published: 11/6/2026
Updated: 11/6/2026
Supported Sensors: Nessus
Risk Information
VPR
Risk Factor: Medium
Score: 4.9
Percentile: 58.41
CVSS v2
Risk Factor: Critical
Base Score: 10
Temporal Score: 7.4
Vector: CVSS2#AV:N/AC:L/Au:N/C:C/I:C/A:C
CVSS Score Source: CVE-2026-27820
CVSS v3
Risk Factor: Critical
Base Score: 9.8
Temporal Score: 8.5
Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Temporal Vector: CVSS:3.0/E:U/RL:O/RC:C
CVSS v4
Risk Factor: Medium
Base Score: 6.3
Threat Score: 1.7
Threat Vector: CVSS:4.0/E:U
Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N
Vulnerability Information
CPE: cpe:/o:huawei:euleros:2.0, p-cpe:/a:huawei:euleros:ruby-help, p-cpe:/a:huawei:euleros:ruby-irb, p-cpe:/a:huawei:euleros:ruby, p-cpe:/a:huawei:euleros:rubygem-bigdecimal, p-cpe:/a:huawei:euleros:rubygem-did_you_mean, p-cpe:/a:huawei:euleros:rubygem-io-console, p-cpe:/a:huawei:euleros:rubygem-json, p-cpe:/a:huawei:euleros:rubygem-openssl, p-cpe:/a:huawei:euleros:rubygem-psych, p-cpe:/a:huawei:euleros:rubygem-rdoc, p-cpe:/a:huawei:euleros:rubygems
Required KB Items: Host/local_checks_enabled, Host/cpu, Host/EulerOS/release, Host/EulerOS/rpm-list, Host/EulerOS/sp
Excluded KB Items: Host/EulerOS/uvp_version
Exploit Ease: No known exploits are available
Patch Publication Date: 11/5/2026
Vulnerability Publication Date: 7/12/2025
Reference Information
CVE: CVE-2025-24294, CVE-2026-27820, CVE-2026-47240, CVE-2026-47241, CVE-2026-80212, CVE-2026-80213