VulnerabilityPublished 14 Oct 2024Updated 29 Oct 2024

CVE-2024-49214: haproxy · Authentication Bypass by Spoofing

Affects haproxySource CVE Database V5

Not known to be exploited · CVSS 5.3 Medium : upgrade to 3.0.5 or 2.9.11 when convenient.

Data as of 26 Oct 2026, 14:05 UTC

CVSS 3.1 base score

5.3Medium

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

EPSS: 0.5% chance of exploitation in 30 days – higher than 43% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 3.0.5, 2.9.11

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

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

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

Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
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).
Availability: None: There is no impact to availability within the impacted component.
Confidentiality: None: There is no loss of confidentiality within the impacted component.
Integrity: Low: Modification of data is possible, but the attacker does not have control over the consequence of a modification, or the amount of modification is limited. The data modification does not have a direct, serious impact on the impacted 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.
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.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 14 Oct 2024
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 haproxy/haproxy to 3.0.5 or 2.9.11.

Affected software

Product	Affected	Fixed in
GitHubhaproxy/haproxy`pkg:github/haproxy/haproxy`Other threats	Affected <2.9.11 <3.0.5 =3.1-dev7	Fixed in 2.9.11 3.0.5

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

AI-suggested

Upgrade HAProxy to the latest patched versions: 2.9.11 or later, 3.0.5 or later, and 3.1-dev7 or later where this vulnerability is fixed.
If immediate patching is not feasible, consider disabling QUIC support in HAProxy to eliminate the attack vector related to 0-RTT sessions.
Implement additional layers of access control beyond IP filtering, such as mutual TLS authentication or application-layer authentication, to reduce reliance on IP-based controls.
Monitor HAProxy logs for unusual 0-RTT session attempts or unexpected source IP addresses to detect potential exploitation attempts.
Employ network-level protections like firewall rules or intrusion detection systems to restrict traffic to trusted sources and detect spoofing attempts.
Review and tighten IP allow/block list configurations to ensure they are as restrictive as possible.
Conduct regular security assessments and penetration testing focusing on HAProxy configurations and QUIC protocol usage to identify residual risks.

Description

QUIC in HAProxy 3.1.x before 3.1-dev7, 3.0.x before 3.0.5, and 2.9.x before 2.9.11 allows opening a 0-RTT session with a spoofed IP address. This can bypass the IP allow/block list functionality.

Impact

This vulnerability can undermine the effectiveness of IP allow/block lists, a common security control used to restrict access to sensitive services or networks. By bypassing these controls, attackers can gain unauthorized access to backend systems or services protected by HAProxy, potentially leading to unauthorized data manipulation or lateral movement within the network. Although confidentiality and availability are not directly impacted, the integrity of access control is compromised, which can facilitate further attacks or unauthorized activities. Organizations that rely heavily on IP-based filtering for perimeter defense or internal segmentation are particularly at risk. The ease of exploitation without authentication or user interaction increases the threat level, especially in environments exposed to untrusted networks. The lack of known exploits in the wild suggests limited current impact, but the vulnerability should be addressed promptly to prevent future abuse. Failure to mitigate this issue could lead to compliance violations and increased risk of breach in regulated industries.

CWE-290Authentication Bypass by Spoofing (opens in a new tab)
Base weaknessOWASP Top 10 A07:2025: Authentication Failures (opens in a new tab)
This attack-focused weakness is caused by incorrectly implemented authentication schemes that are subject to spoofing attacks.
OWASP Cheat Sheets
REST Security (opens in a new tab)
JSON Web Token for Java (opens in a new tab)
OWASP Authentication (opens in a new tab)
OWASP ASVS 4.0.3
V3.5.1 (opens in a new tab)
V2.8.5 (opens in a new tab)
V2.8.4 (opens in a new tab)
Attack patterns
Creating a Rogue Certification Authority Certificate (opens in a new tab)
Web Services API Signature Forgery Leveraging Hash Function Extension Weakness (opens in a new tab)
Signature Spoof (opens in a new tab)
Signature Spoofing by Misrepresentation (opens in a new tab)
Session Credential Falsification through Prediction (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

Community reviews

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 26 Feb 2026, 00:24 UTC

WeaknessesCWE-290

Technical details

References

Community reviews

Related threats