Apache Traffic Server: Invalid Accept-Encoding can force forwarding requests
Noroxi assessment
Priority: Monitor (action score 32/100)
- The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
- Probability of exploitation in the next 30 days: 1% (FIRST EPSS); higher than 64.7% of all records.
- Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
- Fixed version: Apache Software Foundation Apache Traffic Server 8.1.11.
Low priority for now. Upgrade to Apache Software Foundation Apache Traffic Server 8.1.11 or later.
Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it
Primary sources: NVD · CVE.org · FIRST EPSS
Invalid Accept-Encoding header can cause Apache Traffic Server to fail cache lookup and force forwarding requests. This issue affects Apache Traffic Server: from 8.0.0 through 8.1.10, from 9.0.0 through 9.2.4. Users are recommended to upgrade to version 8.1.11 or 9.2.5, which fixes the issue.
- Published
- Jul 26, 2024
- Updated
- Jun 17, 2026
- EPSS
- 1.0% · 64th percentile
- CWE
- CWE-20
Report tools
Action score
32
Monitor
Low priority for now.
- CVSS
- 32 / 40 · 8.2 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 0 / 30 · 1.0%
CISA SSVC decision
- Exploitation
- none
- Automatable
- no
- Technical impact
- partial
Vulnrichment: CISA's decision-tree inputs.
Get told when this record changes
- Not in KEV: no record of exploitation in the wild
- No public exploit code on record
- A fix has been released
If any of these changes, we'll tell you in the daily email digest.
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Noroxi analysis
What does it mean in your environment?
The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.
We use this product, ask for helpAffected systems
Is your version affected?
Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.
| Vendor | Product | CPE |
|---|---|---|
| apache | traffic server | cpe:2.3:a:apache:traffic_server |
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- apache traffic server8.0.0 and later · before 8.1.11
- apache traffic server9.0.0 and later · before 9.2.5
Versions reported by the vendor
Affected version ranges reported by the assigning authority (apache). Independent of NVD's CPE analysis and usually ahead of it.
Apache Software Foundation Apache Traffic Server
- 8.0.0 and later · up to and including 8.1.10affected · semver
- 9.0.0 and later · up to and including 9.2.4affected · semver
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| Debian:11 | trafficserver | before 8.1.11+ds-0+deb11u1 | 8.1.11+ds-0+deb11u1 |
| Debian:12 | trafficserver | before 9.2.5+ds-0+deb12u1 | 9.2.5+ds-0+deb12u1 |
Same product
apache: all recordsOther highest-scoring records for the same primary product.
- CVE-2024-31309Apache Traffic Server: HTTP/2 CONTINUATION frames can be utilized for DoS attack58Plan
- CVE-2023-39456Apache Traffic Server: Malformed http/2 frames can cause an abort47Plan
- CVE-2015-3249The HTTP/2 experimental feature in Apache Traffic Server 5.3.x before 5.3.1 allows remote attackers to cause a denial of service (out-of-bou41Plan
Published before and after this one in the same product
- ← EarlierCVE-2023-38522Jul 26, 2024 · Apache Traffic Server: Incomplete field name check allows request smuggling30Monitor
- ← EarlierCVE-2024-35161Jul 26, 2024 · Apache Traffic Server: Incomplete check for chunked trailer section allows request smuggling30Monitor
- Later →CVE-2024-38479Nov 14, 2024 · Apache Traffic Server: Cache key plugin is vulnerable to cache poisoning attack30Monitor
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
| Product / package | Fixed version | Source |
|---|---|---|
| Apache Software Foundation Apache Traffic Server | 8.1.11 · description | Vendor (CNA) |
| debian:trafficserver | 9.2.5+ds-0+deb12u1 · Debian:12 | Package registry (OSV) |
Exploit status
No known public exploit
No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.
Research context
For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.
Timeline
From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.
No dated events beyond publication.
FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).
Patch and commit links
Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.
No commit or PR link among the references.
Credits
All researchersFinders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.
- Min Chenreporter
Variant candidates
Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.
- CVE-2024-31309107 days apartApache Traffic Server: HTTP/2 CONTINUATION frames can be utilized for DoS attack58Plan
- CVE-2023-39456283 days apartApache Traffic Server: Malformed http/2 frames can cause an abort47Plan
- CVE-2022-47185352 days apartApache Traffic Server: Invalid Range header causes a crash31Monitor
- CVE-2023-30631408 days apartApache Traffic Server: Configuration option to block the PUSH method in ATS didn't work31Monitor
- CVE-2024-38479111 days apartApache Traffic Server: Cache key plugin is vulnerable to cache poisoning attack30Monitor
- CVE-2024-50305111 days apartApache Traffic Server: Valid Host field value can cause crashes30Monitor
Chain candidates
An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.
—
Bug bounty scope
No known public program.
Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).
Technical details
Attack conditions
- Anyone who can reach it over the internet can trigger it.
- No account or password is required.
- No user action is required.
- No special conditions are required; it is repeatable.
If successful
- Confidentiality
- none
- Integrity
- high · data or configuration can be modified
- Availability
- low · the service can be disrupted
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality impact
- None
- Integrity impact
- High
- Availability impact
- Low
Weakness class (CWE)
CWE-20 · Improper Input ValidationCVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:L
nvd-primary
Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
Attack patterns (CAPEC)
- Buffer Overflow via Environment VariablesCAPEC-10likelihood: High · High
- Server Side Include (SSI) InjectionCAPEC-101likelihood: High · High
- Cross Zone ScriptingCAPEC-104likelihood: Medium · High
- Command Line Execution through SQL InjectionCAPEC-108likelihood: Low · Very High
- Object Relational Mapping InjectionCAPEC-109likelihood: Low · High
- SQL Injection through SOAP Parameter TamperingCAPEC-110likelihood: High · Very High
- Double EncodingCAPEC-120likelihood: Low · Medium
- Subverting Environment Variable ValuesCAPEC-13likelihood: High · Very High
ATT&CK techniques
- Obfuscated Files or InformationT1027
- Masquerading: Invalid Code SignatureT1036.001
- Steal Web Session CookieT1539
- Subvert Trust Controls: Code SigningT1553.002
- Impair Defenses:Impair Command History LoggingT1562.003
- Hijack Execution Flow:Dynamic Linker HijackingT1574.006
- Hijack Execution Flow:Path Interception by PATH Environment VariableT1574.007
Change log
- Fix✗ → ✓
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References
Show all references (1 more)Show less
Vendor advisories and official records. Exploit/PoC links are deliberately left out.