VulnerabilityPublished 21 Sep 2022Updated 28 May 2025

CVE-2022-38177: ISC BIND9 · Memory Leak

Affects ISC BIND9Source CVE Database V5

Not known to be exploited · CVSS 7.5 High : upgrade to 9.16.33 soon.

Data as of 26 Oct 2026, 14:05 UTC

CVSS 3.1 base score

7.5High

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 3.2% chance of exploitation in 30 days – higher than 88% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 9.16.33

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Attack Vector: Network
Attack Complexity: Low
Privileges Required: None
User Interaction: None
Scope: Unchanged
Confidentiality: None
Integrity: None
Availability: High

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: None: There is no loss of confidentiality within the impacted component.
Integrity: None: There is no loss of integrity within the impacted component.
Availability: High: There is total loss of availability, resulting in the attacker being able to fully deny access to resources in the impacted component; this loss is either sustained (while the attacker continues to deliver the attack) or persistent (the condition persists even after the attack has completed). Alternatively, the attacker has the ability to deny some availability, but the loss of availability presents a direct, serious consequence to the impacted component (e.g., the attacker cannot disrupt existing connections, but can prevent new connections; the attacker can repeatedly exploit a vulnerability that, in each instance of a successful attack, leaks a only small amount of memory, but after repeated exploitation causes a service to become completely unavailable).

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 21 Sep 2022
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade isc/bind9 to 9.16.33.

Affected software

Product	Affected	Fixed in
Iscisc/bind9`pkg:rpm/isc/bind9`Other threats	Affected <9.16.33	Fixed in 9.16.33

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

Organizations should promptly identify if their DNS infrastructure uses affected BIND9 versions and plan immediate upgrades to patched versions once available from ISC. In the interim, network-level mitigations can be applied, such as filtering or rate-limiting DNS responses with malformed ECDSA signatures to reduce exposure to spoofed malicious packets. Deploying DNS response validation and anomaly detection tools can help identify suspicious DNSSEC signature anomalies. Where possible, segregate DNS resolver roles and limit exposure of recursive resolvers to untrusted networks. Employing DNS firewalling and response policy zones (RPZ) may help mitigate spoofed responses. Monitoring memory usage and setting resource limits for the named process can provide early warning and containment of memory exhaustion. Organizations should also ensure that their DNS infrastructure is behind robust network perimeter defenses, including anti-spoofing measures (e.g., BCP38) to reduce the risk of receiving spoofed packets. Finally, maintain up-to-date backups and incident response plans to quickly recover from potential DNS service disruptions.

Description

By spoofing the target resolver with responses that have a malformed ECDSA signature, an attacker can trigger a small memory leak. It is possible to gradually erode available memory to the point where named crashes for lack of resources.

Impact

For European organizations, the impact of this vulnerability can be significant, especially for those relying on BIND9 as their authoritative or recursive DNS resolver. A successful exploitation leads to a denial of service by crashing the DNS server, which can disrupt domain name resolution services critical for internal and external communications, web services, and other network-dependent operations. This can affect ISPs, enterprises, government agencies, and critical infrastructure providers. DNS outages can cause cascading failures in business operations, loss of availability of web portals, email, and other essential services. Since DNSSEC is used to ensure DNS integrity and authenticity, the vulnerability also undermines trust in DNS responses, potentially complicating incident response and recovery. Although the vulnerability does not directly compromise confidentiality or integrity, the availability impact alone can cause operational and reputational damage. European organizations with public-facing DNS infrastructure or those providing DNS services to customers are particularly at risk. Additionally, organizations in sectors such as finance, healthcare, and government, where DNS availability is critical, may face heightened risks. The absence of known exploits in the wild reduces immediate threat but does not eliminate the risk, especially as attackers may develop exploits over time.

CWE-401Missing Release of Memory after Effective Lifetime (opens in a new tab)
Variant weaknessLikelihood of exploit: Medium
The product does not sufficiently track and release allocated memory after it has been used, making the memory unavailable for reallocation and reuse.
Implementation · Libraries or Frameworks
Choose a language or tool that provides automatic memory management, or makes manual memory management less error-prone.
Architecture and Design
Use an abstraction library to abstract away risky APIs. Not a complete solution.
Architecture and Design · Build and Compilation
Consider using the Boehm-Demers-Weiser garbage collector (bdwgc), which can help avoid leaks.
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 7 Jul 2025, 08:40 UTC

WeaknessesCWE-401

Technical details

References

Community reviews

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