Gentoo update for Unbound
| Risk | Medium |
| Patch available | YES |
| Number of vulnerabilities | 3 |
| CVE-ID | CVE-2022-30698 CVE-2022-30699 CVE-2022-3204 |
| CWE-ID | CWE-341 CWE-400 |
| Exploitation vector | Network |
| Public exploit | N/A |
| Vulnerable software Subscribe |
Gentoo Linux Operating systems & Components / Operating system net-dns/unbound Operating systems & Components / Operating system package or component |
| Vendor | Gentoo |
Security Bulletin
This security bulletin contains information about 3 vulnerabilities.
1) Predictable from Observable State
EUVDB-ID: #VU66548
Risk: Medium
CVSSv3.1: 6.5 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N/E:U/RL:O/RC:C]
CVE-ID: CVE-2022-30698
CWE-ID:
CWE-341 - Predictable from Observable State
Exploit availability: No
DescriptionThe vulnerability allows a remote attacker to poison DNS cache.
The vulnerability exists due to the way Unbound handles delegation information expiration event. A remote attacker who controls a rouge DNS server can force the Unbound instance to cache incorrect information about subdomain delegation and permanently poison the DNS cache, e.g. perform the "ghost domain names" attack.
The attack is carried out when Unbound is queried for a subdomain of a rogue domain name. The rogue nameserver returns delegation information for the subdomain that updates Unbound's delegation cache. This action can be repeated before expiry of the delegation information by querying Unbound for a second level subdomain which the rogue nameserver provides new delegation information. Since Unbound is a child-centric resolver, the ever-updating child delegation information can keep a rogue domain name resolvable long after revocation. MitigationUpdate the affected packages.
net-dns/unbound to version: 1.16.3
Gentoo Linux: All versions
net-dns/unbound: before 1.16.3
External linkshttp://security.gentoo.org/glsa/202212-02
Q & A
Can this vulnerability be exploited remotely?
Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.
Is there known malware, which exploits this vulnerability?
No. We are not aware of malware exploiting this vulnerability.
2) Predictable from Observable State
EUVDB-ID: #VU66547
Risk: Medium
CVSSv3.1: 6.5 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N/E:U/RL:O/RC:C]
CVE-ID: CVE-2022-30699
CWE-ID:
CWE-341 - Predictable from Observable State
Exploit availability: No
DescriptionThe vulnerability allows a remote attacker to poison DNS cache.
The vulnerability exists due to the way Unbound handles delegation information expiration event. A remote attacker who controls a rouge DNS server can force the Unbound instance to cache incorrect information about domain delegation and permanently poison the DNS cache, e.g. perform the "ghost domain names" attack.
The attack is perform when Unbound is queried for a rogue domain name, which cached delegation information is about to expire. The rogue nameserver delays the response until the cached delegation information expires. Upon receiving the delayed answer containing the delegation information, Unbound overwrites the now expired entries.
MitigationUpdate the affected packages.
net-dns/unbound to version: 1.16.3
Gentoo Linux: All versions
net-dns/unbound: before 1.16.3
External linkshttp://security.gentoo.org/glsa/202212-02
Q & A
Can this vulnerability be exploited remotely?
Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.
Is there known malware, which exploits this vulnerability?
No. We are not aware of malware exploiting this vulnerability.
3) Resource exhaustion
EUVDB-ID: #VU69407
Risk: Medium
CVSSv3.1: 6.5 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C]
CVE-ID: CVE-2022-3204
CWE-ID:
CWE-400 - Resource exhaustion
Exploit availability: No
DescriptionThe vulnerability allows a remote attacker to perform a denial of service (DoS) attack.
The vulnerability exists due to application does not properly control consumption of internal resources when processing a malicious delegation with a considerable number of non responsive nameservers. A remote attacker can trigger CPU high usage and perform a denial of service (DoS) attack.
The attack is known as "Non-Responsive Delegation Attack" (NRDelegation Attack).
MitigationUpdate the affected packages.
net-dns/unbound to version: 1.16.3
Gentoo Linux: All versions
net-dns/unbound: before 1.16.3
External linkshttp://security.gentoo.org/glsa/202212-02
Q & A
Can this vulnerability be exploited remotely?
Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.
Is there known malware, which exploits this vulnerability?
No. We are not aware of malware exploiting this vulnerability.
