F5 is upgrading its customer support chat feature on My.F5.com. Chat support will be unavailable from 6am-10am PST on 1/20/26. Refer to K000159584 for details.

Forum Discussion

misch43's avatar
misch43
Icon for Nimbostratus rankNimbostratus
Jan 17, 2023

ASM: Apostroph (0x27) char in header value

Hi, we see HTTP requests comming in where the User-Agent header ist delimited by an apostroph (0x27 ASCII). The ASM flags this as a violation and suggests me to allow that char. As far as I unterst...
security
Juergen_Mang's avatar
Juergen_Mang
Icon for MVP rankMVP
Jan 17, 2023

It depends on:

  • if you want to allow the client, you must disable this protection
  • else ignore the suggestion

There are some browsers, mostly from smartphones, that violates the rfc's and sends non-ascii characters in headers.