Apache Software Foundation Apache HTTP Server
Not confirmed exploited. 1 of 8 rule sources name it.
In Apache httpd before 2.2.34 and 2.4.x before 2.4.27, the value placeholder in [Proxy-]Authorization headers of type 'Digest' was not initialized or reset before or between successive key=value assignments by mod_auth_digest. Providing an… More
In Apache httpd before 2.2.34 and 2.4.x before 2.4.27, the value placeholder in [Proxy-]Authorization headers of type 'Digest' was not initialized or reset before or between successive key=value assignments by mod_auth_digest. Providing an initial key with no '=' assignment could reflect the stale value of uninitialized pool memory used by the prior request, leading to leakage of potentially confidential information, and a segfault in other cases resulting in denial of service.
Edge coverage
Claimed by vendorsAsk Vigil
AI · answers from this pageWorkers AI (Llama 3.3). Can be wrong: check the cited source.
Public exploits
None foundNo exploit in Exploit-DB or Metasploit, and no scanner template. That lowers, but doesn't remove, the chance of mass exploitation.
Timeline
- 2017-07-13CVE publishedCVE List
- 2026-09-16F5 rule names itEarliest entry we can see is an update
Vendor statements
QuotedCloudflareWAF Managed Rules
The CVE predates the oldest entry in this vendor's public feed, so a rule may exist that we cannot see.
AWSAWS WAF Managed Rules
The CVE predates the oldest entry in this vendor's public feed, so a rule may exist that we cannot see.
Microsoft AzureFront Door and Application Gateway WAF (DRS)
We found no public statement from this vendor naming this CVE. That is not proof of no protection: generic rules may still catch it. The rule tables name CVEs but carry no dates, so Azure is left out of every time-to-rule figure.
Google CloudCloud Armor preconfigured WAF rules
The CVE predates the oldest entry in this vendor's public feed, so a rule may exist that we cannot see.
FastlyNext-Gen WAF virtual patches
The CVE predates the oldest entry in this vendor's public feed, so a rule may exist that we cannot see.
F5Attack signatures (Distributed Cloud WAF)
Named by 2026-09-16; the first entry is an update, so the rule may be older.
Updated: signature 200012027 "Digest authentication uninitialized memory reflection" (Denial of Service, risk High), systems: Apache, JBoss. References: CVE-2017-9788.
AkamaiApp & API Protector (Adaptive Security Engine)
This vendor publishes no machine-readable rule changelog we can check.
OWASP CRSCore Rule Set (open source, used inside many WAFs)
The CVE predates the oldest entry in this vendor's public feed, so a rule may exist that we cannot see.
Social
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