CVE-2019-12529

high-risk
Published 2019-07-11

An issue was discovered in Squid 2.x through 2.7.STABLE9, 3.x through 3.5.28, and 4.x through 4.7. When Squid is configured to use Basic Authentication, the Proxy-Authorization header is parsed via uudecode. uudecode determines how many bytes will be decoded by iterating over the input and checking its table. The length is then used to start decoding the string. There are no checks to ensure that the length it calculates isn't greater than the input buffer. This leads to adjacent memory being decoded as well. An attacker would not be able to retrieve the decoded data unless the Squid maintainer had configured the display of usernames on error pages.

Do I need to act?

!
16.2% chance of exploitation in next 30 days
EPSS score — higher than 84% of all CVEs
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Not on CISA KEV list
No confirmed active exploitation reported to CISA
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Patch status unknown
Check vendor advisories for fix availability and mitigation guidance
5
CVSS 5.9/10 Medium
NETWORK / HIGH complexity

References (24)

Third Party Advisory https://usn.ubuntu.com/4065-1/
Third Party Advisory https://usn.ubuntu.com/4065-2/
and 4 more references
51
/ 100
high-risk
Severity 18/34 · Moderate
Exploitability 13/34 · Low
Exposure 20/34 · Moderate