CVE-2023-5824VulnerabilityPublished 3 Nov 2023Updated 6 Nov 2025

CVE-2023-5824: Red Hat Enterprise Linux 8 · Improper Handling of Exceptional Conditions

Affects Red Hat Enterprise Linux 8Source CVE Database V5

Not known to be exploited · CVSS 7.5 High.

Data as of 26 Oct 2026, 06:26 UTC

CVSS 3.1 base score

7.5High

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

EPSS: 3.0% chance of exploitation in 30 days – higher than 87% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

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 3 Nov 2023
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 2026-10-26.

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 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

Affected software

Product	Affected	Fixed in
Red Hatredhat/squid`pkg:rpm/redhat/squid`Other threats	Affected =5.3-3.el8_9.1	Fixed in–

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

AI-suggested

1. Apply official patches from Red Hat as soon as they become available to address this vulnerability directly in Squid. 2. Until patches are applied, consider restricting external access to Squid proxy services to trusted networks only, reducing exposure to potential attackers. 3. Implement monitoring and alerting for abnormal Squid worker process behavior, such as frequent crashes or stalls, to detect exploitation attempts early. 4. Configure Squid to limit the size of cached HTTP response headers more strictly, if possible, or disable caching of headers that could grow excessively. 5. Use network-level protections such as firewalls or intrusion prevention systems to block suspicious HTTP traffic patterns that may trigger the vulnerability. 6. Conduct regular security audits and vulnerability scans focused on proxy services to ensure no other related misconfigurations exist. 7. Educate system administrators about this vulnerability and the importance of timely patch management for critical infrastructure components.

Description

A flaw was found in Squid. The limits applied for validation of HTTP response headers are applied before caching. However, Squid may grow a cached HTTP response header beyond the configured maximum size, causing a stall or crash of the worker process when a large header is retrieved from the disk cache, resulting in a denial of service.

Impact

For European organizations, this vulnerability poses a significant risk to the availability of web proxy and caching services that rely on Squid within Red Hat Enterprise Linux 8 environments. A successful exploitation can cause Squid worker processes to stall or crash, leading to denial of service conditions that disrupt access to cached web content or proxy services. This can impact business continuity, especially for enterprises that depend on Squid for load balancing, content filtering, or bandwidth optimization. Public sector organizations, financial institutions, and large enterprises with strict uptime requirements may experience operational disruptions. Additionally, denial of service attacks exploiting this vulnerability could be used as part of larger multi-vector attacks targeting critical infrastructure. The lack of impact on confidentiality and integrity reduces the risk of data breaches, but the availability impact alone is sufficient to warrant urgent remediation. European organizations with extensive Red Hat Enterprise Linux 8 deployments, particularly those in Germany, France, the UK, and the Netherlands, should be especially vigilant due to the widespread use of Red Hat products in these countries.

References

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 10 Nov 2025, 18:50 UTC

Technical details

References

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